Republican strategist and former White House senior advisor Karl Rove and former White House press secretary for President George W. Bush Dana Perino depart following the State Funeral for former President George H.W. Bush at the National Cathedral, Wednesday, Dec. 5, 2018, in Washington. Andrew Harnik/Pool via REUTERS 

Republican strategist and former White House senior adviser Karl Rove departs following the State Funeral for former President George H.W. Bush at the National Cathedral, Wednesday, Dec. 5, 2018, in Washington. Andrew Harnik/Pool via REUTERS 

Former U.S. Vice President Joe Biden greets White House senior advisors Jared Kushner and Ivanka Trump as they arrive at the state funeral for former U.S. President George H.W. Bush at Washington National Cathedral in Washington, U.S., December 5, 2018. REUTERS/Kevin Lamarque 

Former Vice President Joe Biden and his wife Jill Biden speak with Ivanka Trump, the daughter of President Donald Trump and her husband, President Donald Trump's White House Senior Adviser Jared Kushner, as former Vice President Al Gore speaks to former President Jimmy Carter and former first lady Rosalynn Carter before a State Funeral for former President George H.W. Bush at the National Cathedral,in Washington, U.S., December 5, 2018. Andrew Harnik/Pool via REUTERS 

Former Vice President Joe Biden and his wife Jill Biden speak with Ivanka Trump, the daughter of President Donald Trump and her husband, President Donald Trump's White House Senior Adviser Jared Kushner, as former Vice President Al Gore speaks to former President Jimmy Carter and former first lady Rosalynn Carter before a State Funeral for former President George H.W. Bush at the National Cathedral, Wednesday, Dec. 5, 2018, in Washington. Andrew Harnik/Pool via REUTERS 

President Donald Trump's White House Senior Adviser Stephen Miller and White House deputy chief of staff for communications Bill Shine arrive for a State Funeral for former President George H.W. Bush at the National Cathedral, Wednesday, Dec. 5, 2018, in Washington. Andrew Harnik/Pool via REUTERS 

Former U.S. President George W. Bush dances along with the Warren Easton Charter High School marching band one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush greets Jaymerson George, a member of the Warren Easton Charter High School marching band, one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush delivers a speech at Warren Easton Charter High School one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush dances along with the Warren Easton Charter High School marching band one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush delivers a speech at Warren Easton Charter High School one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush delivers a speech at Warren Easton Charter High School one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush takes a tour of Warren Easton Charter High School one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush delivers a speech at Warren Easton Charter High School one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush delivers a speech at Warren Easton Charter High School one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush delivers a speech at Warren Easton Charter High School one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush listens to a speech while visiting Warren Easton Charter High School one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush poses with the Warren Easton Charter High School marching band one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush poses for a selfie with the Warren Easton Charter High School marching band one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush hugs an employee of Warren Easton Charter High School one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush dances along with the Warren Easton Charter High School marching band one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

New Orleans mayor Mitch Landrieu introduces former U.S. President George W. Bush to an NOPD police officer at Warren Easton Charter High School one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush reacts as he talks to a student at Warren Easton Charter High School one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush and New Orleans Mayor Mitch Landrieu (L) talk to students at Warren Easton Charter High School one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush talks with Ashantae Martin (L) and Ronjae Pleasant at Warren Easton Charter High School one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush talks with Ashantae Martin (L) and Ronjae Pleasant at Warren Easton Charter High School one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana August 28, 2015. At right is former first lady Laura Bush. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush talks with Ashantae Martin (L) and Ronjae Pleasant at Warren Easton Charter High School one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman TPX IMAGES OF THE DAY

Former U.S. President George W. Bush talks with Ashantae Martin (L), and Ronjae Pleasant at Warren Easton Charter High School one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana, August 28, 2015. REUTERS/Jonathan Bachman 

Former U.S. President George W. Bush, accompanied by New Orleans Mayor Mitch Landrieu (L) and former first lady Laura Bush, gestures to the media as he arrives at Warren Easton Charter High School, one day before the ten year anniversary of Hurricane Katrina in New Orleans, Louisiana August 28, 2015. REUTERS/Jonathan Bachman 

Mark Cuban, entrepreneur and owner of the Dallas Mavericks, speaks as moderator Kevin Sullivan, Senior Advisor for External Affairs at the George W. Bush Presidential Center, listens during a moderated conversation at the graduation of the inaugural class of the Presidential Leadership Scholars program, a partnership between the presidential centers of George W. Bush, William J. Clinton, George H.W. Bush, and Lyndon B. Johnson at the George W. Bush Presidential Library in Dallas, Texas July 9, 2015. REUTERS/Mike Stone 

Former New York Mayor Michael Bloomberg stands to receive an honorary Doctor of Laws degree as fellow honorary degree recipients musician Aretha Franklin (L) and former United States President George H.W. Bush (R) applaud during the 363rd Commencement Exercises at Harvard University in Cambridge, Massachusetts May 29, 2014. REUTERS/Brian Snyder (UNITED STATES - Tags: EDUCATION TPX IMAGES OF THE DAY) 

A self-portrait of former U.S. President George W. Bush and a portrait he painted of his father, former U.S. President George H.W. Bush, greet visitors at "The Art of Leadership: A President's Personal Diplomacy" exhibit at the Bush Presidential Library and Museum in Dallas, Texas April 4, 2014. REUTERS/Brandon Wade (UNITED STATES - Tags: POLITICS SOCIETY) 

U.S. President Barack Obama (L) stands alongside (L-R) former presidents George W. Bush, Bill Clinton, George H.W. Bush and Jimmy Carter as they attend the dedication ceremony for the George W. Bush Presidential Center in Dallas, April 25, 2013. Obama is in Texas to stand shoulder-to-shoulder with former president George W. Bush in what could serve as a powerful reminder of the ongoing struggle against terrorism, from the Sept. 11 attacks to the Boston Marathon bombings. REUTERS/Jason Reed (UNITED STATES - Tags: POLITICS) FOR BEST QUALITY IMAGE: ALSO SEE GM1E97T1JAR01 

Republican presidential candidate Mitt Romney (L) picks up the formal endorsement of former President George H.W. Bush and former first lady Barbara Bush in Houston March 29, 2012. REUTERS/Donna Carson (UNITED STATES - Tags: POLITICS ELECTIONS TPX IMAGES OF THE DAY) 

Former U.S. President George H.W. Bush, along with two Marines, performs the coin toss before the Houston Texans played the Cleveland Browns in their NFL football game in Houston November 6, 2011. REUTERS/Richard Carson ( UNITED STATES - Tags: SPORT FOOTBALL) 

Former U.S. Presidents Bill Clinton (3rd L), Jimmy Carter (L), George. H.W. Bush (C) and George W. Bush (2nd R) attend the "All Together Now - A Celebration of Service" at the John F. Kennedy Center for Performing Arts in Washington March 21, 2011. They are joined by Rosalynn Carter (2nd L), Barbara Bush (3rd R) and Laura Bush (R). REUTERS/Jim Young (UNITED STATES - Tags: POLITICS ENTERTAINMENT) 

Former U.S. President George H.W. Bush (R) watches as his son, former President George W. Bush, throws a ceremonial first pitch prior to the start of Game 4 of Major League Baseball's World Series between the San Francisco Giants and the Texas Rangers, in Arlington, Texas, October 31, 2010. REUTERS/Brian Snyder (UNITED STATES - Tags: SPORT BASEBALL IMAGES OF THE DAY) 

Former Soviet Union President Mikhail Gorbachev (L) reaches out his hand to former German Chancellor Helmut Kohl (R) as former U.S. President George Bush applauds while attending a ceremony of the Konrad-Adenauer foundation to mark the upcoming 20-year anniversary, in November, of the fall of the wall which once divided communist East Berlin from capitalist west Berlin, in Berlin October 31, 2009. REUTERS/Fabrizio Bensch (GERMANY POLITICS IMAGES OF THE DAY) 

U.S. President Barack Obama is introduced to speak by former President George H.W. Bush at the Points of Light forum at Texas A&M University in College Station, Texas October 16, 2009. REUTERS/Kevin Lamarque (UNITED STATES POLITICS) 

Students play basketball in the courtyard of Al-Motamayzat High School for girls in Baghdad February 9, 2009. For Baghdad schools, Saddam Hussein, George W. Bush and the sectarian slaughter unleashed after U.S. troops invaded six years ago are non-issues, banned from books and their discussion taboo. Picture taken February 9, 2009. REUTERS/Thaier al-Sudani (IRAQ) 

Former U.S. President George Bush leaves the U.S. Capitol following the inauguration ceremony for President Barack Obama in Washington, January 20, 2009. REUTERS/Mike Segar (UNITED STATES) 

From L-R, former President George H.W. Bush, President-elect Barack Obama, President George W. Bush, former President Bill Clinton and former President Jimmy Carter meet in the Oval Office of the White House in Washington January 7, 2009. REUTERS/Kevin Lamarque (UNITED STATES) 

(L-R) Former President President George H.W. Bush, President-elect Barack Obama, U.S. President George W. Bush, former President Bill Clinton and former President Jimmy Carter meet in the Oval Office of the White House in Washington January 7, 2009. REUTERS/Kevin Lamarque (UNITED STATES) 

U.S. President George W. Bush (R) speaks as President-elect Barack Obama (C) looks over his shoulder during a meeting with former U.S. Presidents in the Oval Office of the White House in Washington January 7, 2009. Pictured at left is former President George H.W. Bush. REUTERS/Kevin Lamarque (UNITED STATES) 

U.S. President George W. Bush (C) meets with former President George H.W. Bush (L), President-elect Barack Obama (2nd L), former President Bill Clinton (2nd R) and former President Jimmy Carter (R) in the Oval Office of the White House in Washington January 7, 2009. REUTERS/Kevin Lamarque (UNITED STATES) 

U.S. President George W. Bush comments on the automaker's industry in the Roosevelt Room at the White House in Washington, December 19, 2008. President Bush said the government will provide ailing U.S. automakers financial aid while they implement plans to restructure because otherwise their collapse could send the economy into a deeper and longer recession. The U.S. government will offer up to $17.4 billion in loans to the ailing U.S. automakers and expects General Motors and Chrysler to access the money immediately, a senior administration official said today. REUTERS/Jim Young (UNITED STATES) 

U.S. President George W. Bush leaves the Roosevelt Room after making comments on the automaker's industry at the White House in Washington, December 19, 2008. President Bush said the government will provide ailing U.S. automakers financial aid while they implement plans to restructure because otherwise their collapse could send the economy into a deeper and longer recession. The U.S. government will offer up to $17.4 billion in loans to the ailing U.S. automakers and expects General Motors and Chrysler to access the money immediately, a senior administration official said today. REUTERS/Jim Young (UNITED STATES) 

U.S. President George W. Bush arrives to make comments on the automaker's industry in the Roosevelt Room at the White House in Washington, December 19, 2008. President Bush said the government will provide ailing U.S. automakers financial aid while they implement plans to restructure because otherwise their collapse could send the economy into a deeper and longer recession. The U.S. government will offer up to $17.4 billion in loans to the ailing U.S. automakers and expects General Motors and Chrysler to access the money immediately, a senior administration official said today. REUTERS/Jim Young (UNITED STATES) 

U.S. President George W. Bush comments on the automaker's industry in the Roosevelt Room at the White House in Washington, December 19, 2008. President Bush said the government will provide ailing U.S. automakers financial aid while they implement plans to restructure because otherwise their collapse could send the economy into a deeper and longer recession. The U.S. government will offer up to $17.4 billion in loans to the ailing U.S. automakers and expects General Motors and Chrysler to access the money immediately, a senior administration official said today. REUTERS/Jim Young (UNITED STATES) 

U.S. President George W. Bush leaves the Roosevelt Room after making comments on the automaker's industry in at the White House in Washington, December 19, 2008. President Bush said the government will provide ailing U.S. automakers financial aid while they implement plans to restructure because otherwise their collapse could send the economy into a deeper and longer recession. The U.S. government will offer up to $17.4 billion in loans to the ailing U.S. automakers and expects General Motors and Chrysler to access the money immediately, a senior administration official said today. REUTERS/Jim Young (UNITED STATES) 

U.S. President George W. Bush leaves the Roosevelt Room after making comments on the automaker's industry at the White House in Washington, December 19, 2008. President Bush said the government will provide ailing U.S. automakers financial aid while they implement plans to restructure because otherwise their collapse could send the economy into a deeper and longer recession. The U.S. government will offer up to $17.4 billion in loans to the ailing U.S. automakers and expects General Motors and Chrysler to access the money immediately, a senior administration official said today. REUTERS/Jim Young (UNITED STATES) 

Senior White House staff walk behind U.S. President George W. Bush (not shown) after arriving at the White House in Washington after attending the FBI Academy graduation in Quantico, Virginia, October 30, 2008. From L-R are: Deputy Chief of Staff Blake Gottesman, Counsel to the President Fred Fielding, and Chief of Staff Josh Bolten. REUTERS/Larry Downing (UNITED STATES) 

Former Soviet leader Mikhail Gorbachev (C) accepts applause after the presentation of the Liberty Medal by former U.S. President George H.W. Bush (L) and Constitution Center CEO and President Joe Torsella (R) at the National Constitution Center in Philadelphia, Pennsylvania, September 18, 2008. Gorbachev is the 2008 recipient of the award that recognizes individuals and organizations that have demonstrated leadership and vision in the pursuit of liberty of conscience or freedom from oppression, ignorance, or deprivation. REUTERS/Tim Shaffer (UNITED STATES) 

Former Soviet leader Mikhail Gorbachev (C) is presented with the Liberty Medal by former U.S. President George H.W. Bush (R) and Constitution Center CEO and President Joe Torsella at the National Constitution Center in Philadelphia, Pennsylvania, September 18, 2008. Gorbachev is the 2008 recipient of the award that recognizes individuals and organizations that have demonstrated leadership and vision in the pursuit of liberty of conscience or freedom from oppression, ignorance, or deprivation. REUTERS/Tim Shaffer (UNITED STATES) 

U.S. President George W. Bush and first lady, Laura Bush, are joined by Vice President Cheney and his wife, as they join senior White House staff members on the South Lawn of the White House for a moment of silence to honor the 7-year anniversary of the attacks on the United States on Sept. 11, 2001 in Washington, September 11, 2008. REUTERS/Larry Downing (UNITED STATES) 

U.S. President George W. Bush and Vice President Dick Cheney walk towards the Oval Office after they joined senior White House staff members on the South Lawn of the White House for a moment of silence to honor the seventh year anniversary of the attacks on the United States on Sept. 11, 2001 in Washington, September 11, 2008. REUTERS/Larry Downing (UNITED STATES)