U.S. Senator Richard Shelby (R-AL) and Senator Lamar Alexander (R-TN) speak at a U.S. Senate Appropriations Subcommittee hearing on the plan to research, manufacture and distribute a coronavirus vaccine, known as Operation Warp Speed on Capitol Hill in Washington, D.C, U.S., July 2, 2020. Saul Loeb/Pool via REUTERS

U.S. Senator Richard Shelby (R-AL) attends a U.S. Senate Appropriations Subcommittee hearing on the plan to research, manufacture and distribute a coronavirus vaccine, known as Operation Warp Speed on Capitol Hill in Washington, D.C, U.S., July 2, 2020. Saul Loeb/Pool via REUTERS

U.S. Senator Richard Shelby (R-AL) arrives for a closed Senate Republican policy lunch meeting to discuss the response to the coronavirus disease (COVID-19) outbreak with senators on Capitol Hill in Washington, U.S., May 19, 2020. REUTERS/Yuri Gripas

A masked U.S. Senator Richard Shelby (R-AL) points to his Alabama-themed mask outside the U.S. Capitol after senators returned to Capitol Hill amid concerns that their legislative sessions could put lawmakers and staff at risk of contracting the coronavirus in Washington, U.S., May 4, 2020. REUTERS/Leah Millis

Sen. Richard Shelby (R-AL) and Sen. Kelly Loeffler (R-GA) get in an elevator after a luncheon meeting to wrap up work on coronavirus economic aid legislation to prevent the spread of coronavirus disease (COVID-19) in Washington, U.S., March 21, 2020. REUTERS/Mary F. Calvert

Sen. Richard Shelby (R-AL) and Sen. Kelly Loeffler (R-GA) get in an elevator after a luncheon meeting to wrap up work on coronavirus economic aid legislation to prevent the spread of coronavirus disease (COVID-19) in Washington, U.S., March 21, 2020. REUTERS/Mary F. Calvert

Sen. Richard Shelby (R-AL) and Sen. Kelly Loeffler (R-GA) get in an elevator after a luncheon meeting to wrap up work on coronavirus economic aid legislation to prevent the spread of coronavirus disease (COVID-19) in Washington, U.S., March 21, 2020. REUTERS/Mary F. Calvert

Senator Richard Shelby (R-AL) walks down a hallway ahead of a Senate luncheon meeting on response to the coronavirus disease (COVID-19) outbreak in Washington, U.S., March 19, 2020. REUTERS/Tom Brenner

Senator Richard Shelby (R-AL) arrives for the resumption of the Senate impeachment trial of U.S. President Donald Trump at the U.S. Capitol in Washington, U.S., January 31, 2020. REUTERS/Brendan McDermid?

Senator Richard Shelby (R-AL) arrives at the U.S Capitol during U.S. President Donald Trump's Senate impeachment trial in Washington, U.S., January 30, 2020. REUTERS/Amanda Voisard

Senator Richard Shelby (R-AL) arrives at the U.S Capitol during U.S. President Donald Trump's Senate impeachment trial in Washington, U.S., January 30, 2020. REUTERS/Amanda Voisard

U.S. Senator Richard Shelby (R-AL) walks to the Senate Floor ahead of a vote on Capitol Hill in Washington, U.S., December 16, 2019. REUTERS/Tom Brenner

U.S. Senator Richard Shelby (R-AL) walks to the Senate Floor ahead of a vote on Capitol Hill in Washington, U.S., December 16, 2019. REUTERS/Tom Brenner

Senate Judiciary Chairman Lindsey Graham (R-SC) speaks with Senators Richard Shelby (R-AL) and Christopher Coons (D-DE) before a hearing on judicial nominees on Capitol Hill in Washington, U.S., December 4, 2019. REUTERS/Joshua Roberts

Senator Richard Shelby (R-AL) speaks to reporters as he arrives for a vote on Capitol Hill in Washington, U.S., November 6, 2019. REUTERS/Joshua Roberts

Senator Richard Shelby (R-AL) speaks to reporters before attending a vote on Capitol Hill in Washington, U.S., October 22, 2019. REUTERS/Tom Brenner

Sen. Richard Shelby (R-AL) asks a question as Acting Defense Secretary Patrick Shanahan; and Chairman of the Joint Chiefs of Staff Gen. Joseph Dunford testify before a Senate Appropriations Defense Subcommittee hearing on the proposed FY2020 budget for the Defense Department on Capitol Hill in Washington, U.S., May 8, 2019. REUTERS/Aaron P. Bernstein

Senator Richard Shelby (R-AL) speaks to reporters after a vote attempting to override U.S. President Donald Trump's veto of the resolution demanding an end to support of Saudi Arabia's war in Yemen failed on Capitol Hill in Washington, U.S., May 2, 2019. REUTERS/Joshua Roberts

U.S. President Donald Trump and First Lady Melania Trump chat with Alabama Gov. Kay Ivey as they survey damage by a tornado with a FEMA official, along with HHS Secretary Ben Carson, Sen. Richard Shelby (R-AL) and DHS Secretary Kirstjen Nielsen, in Beauregard, Alabama, U.S., March 8, 2019. REUTERS/Mike Theiler

U.S. President Donald Trump and First Lady Melania Trump survey tornado damage with Alabama Gov. Kay Ivey and Lee County’s Emergency Management Agency director Kathy Carson (R) at their sides as they tour the disaster area with U.S. Senator Doug Jones (D-AL), Secretary of Housing and Urban Development Ben Carson, Secretary of Homeland Security Kirstjen Nielsen and U.S. Senator Richard Shelby (R-AL) in Beauregard, Alabama, U.S., March 8, 2019. REUTERS/Mike Theiler

U.S. President Donald Trump and First Lady Melania Trump survey tornado damage with Alabama Gov. Kay Ivey and Lee County’s Emergency Management Agency director Kathy Carson (R) at their sides as they tour the disaster area with U.S. Senator Doug Jones (D-AL), Secretary of Housing and Urban Development Ben Carson, Secretary of Homeland Security Kirstjen Nielsen and U.S. Senator Richard Shelby (R-AL) in Beauregard, Alabama, U.S., March 8, 2019. REUTERS/Mike Theiler

U.S. President Donald Trump and First Lady Melania Trump survey tornado damage with Alabama Gov. Kay Ivey and Lee County’s Emergency Management Agency director Kathy Carson (R) at their sides as they tour the disaster area with U.S. Senator Doug Jones (D-AL), Secretary of Housing and Urban Development Ben Carson, Secretary of Homeland Security Kirstjen Nielsen and U.S. Senator Richard Shelby (R-AL) in Beauregard, Alabama, U.S., March 8, 2019. REUTERS/Mike Theiler

U.S. Senator Richard Shelby (R-AL) speaks to reporters as he arrives for the weekly Republican Party caucus luncheon at the U.S. Capitol in Washington, U.S. February 26, 2019. REUTERS/Jonathan Ernst

Sen. Richard Shelby (R-AL) speaks to the media at the U.S. Capitol after a tentative deal is set to avert a second partial government shutdown in Washington, U.S., February 12, 2019. REUTERS/Mary F. Calvert

Sen. Richard Shelby (R-AL) speaks to the media at the U.S. Capitol after a tentative deal is set to avert a second partial government shutdown in Washington, U.S., February 12, 2019. REUTERS/Mary F. Calvert

Sen. Richard Shelby (R-AL), departs a meeting with U.S. House-Senate conferees, to receive a closed briefing from U.S. Border Patrol career professionals, who discuss "the challenges they face protecting the U.S.-Mexico border," at the U.S. Capitol in Washington, U.S., February 6, 2019. REUTERS/Mary F. Calvert

Sen. John Hoeven (R-ND), Sen. Shelley Moore Capito (R-WV) and Sen. Richard Shelby (R-AL), speak to reporters after a meeting with U.S. House-Senate conferees, to receive a closed briefing from U.S. Border Patrol career professionals, who discuss "the challenges they face protecting the U.S.-Mexico border," at the U.S. Capitol in Washington, U.S., February 6, 2019. REUTERS/Mary F. Calvert

Sen. John Hoeven (R-ND), Sen. Shelley Moore Capito (R-WV) and Sen. Richard Shelby (R-AL), speak to reporters after a meeting with U.S. House-Senate conferees, to receive a closed briefing from U.S. Border Patrol career professionals, who discuss “the challenges they face protecting the U.S.-Mexico border," at the U.S. Capitol in Washington, U.S., February 6, 2019. REUTERS/Mary F. Calvert

Sen. Richard Shelby (R-AL) arrives for a meeting with U.S. House-Senate conferees to receive a closed briefing from U.S. Border Patrol career professionals, who discuss "the challenges they face protecting the U.S.-Mexico border" at the U.S. Capitol in Washington, U.S., February 6, 2019. REUTERS/Mary F. Calvert

Sen. Richard Shelby (R-AL) arrives for a meeting with U.S. House-Senate conferees to receive a closed briefing from U.S. Border Patrol career professionals, who discuss "the challenges they face protecting the U.S.-Mexico border" at the U.S. Capitol in Washington, U.S., February 6, 2019. REUTERS/Mary F. Calvert

U.S. Senators Richard Shelby (R-AL) and Patrick Leahy (D-VT) talk with House Appropriations Committee Chair Rep. Nita Lowey (D-NY) as a bipartisan group of lawmakers meet to discuss border security as part of government funding legislation on Capitol Hill in Washington, U.S., January 30, 2019. REUTERS/Yuri Gripas

U.S. Senator Patrick Leahy (D-VT) checks a text next to felllow Senators Richard Shelby (R-AL), John Hoeven (R-ND) and Shelley Moore Caputo (R-WV) as House-Senate conferees meet on border security to discuss Homeland Security funding legislation on Capitol Hill in Washington, U.S., January 30, 2019. REUTERS/Yuri Gripas

U.S. Senator Roy Blunt (R-MO), Senator Richard Shelby (R-AL), Senator Patrick Leahy (D-VT) and Senator Dick Durbin (D-IL) talk as a bipartisan group of U.S. lawmakers gathers to hold a first public negotiating session over the U.S. federal government shutdown and border security on Capitol Hill in Washington, U.S. January 30, 2019. REUTERS/Yuri Gripas

U.S. Senate Majority Leader Mitch McConnell (R-KY) and Senator Richard Shelby (R-AL) return to the Capitol after meeting with U.S. President Donald Trump at the White House, as deadlines for a federal government shutdown loom in Washington, U.S. December 21, 2018. REUTERS/Jonathan Ernst

U.S. Senate Majority Leader Mitch McConnell (R-KY) and Senator Richard Shelby (R-AL) board an elevator to depart the Capitol to go to the White House to meet with U.S. President Donald Trump, as members of the legislative branch are facing deadlines for a potential federal government shutdown, in Washington, U.S. December 21, 2018. REUTERS/Jonathan Ernst

U.S. Senate Majority Leader Mitch McConnell (R-KY) and Senator Richard Shelby (R-AL) board an elevator to depart the Capitol to go to the White House to meet with U.S. President Donald Trump, as members of the legislative branch are facing deadlines for a potential federal government shutdown, in Washington, U.S. December 21, 2018. REUTERS/Jonathan Ernst

U.S. Senate Majority Leader Mitch McConnell (R-KY) and Senator Richard Shelby (R-AL) depart the Capitol to go to the White House to meet with U.S. President Donald Trump, as members of the legislative branch are facing deadlines for a potential federal government shutdown, in Washington, U.S. December 21, 2018. REUTERS/Jonathan Ernst

Senator Richard Shelby (R-AL) speaks to journalists as he arrives for a vote on Capitol Hill in Washington, U.S., September 24, 2018. REUTERS/Joshua Roberts

Sen. Jeff Flake, R-Ariz., center, and his wife Cheryl Flake, left, arrive in the Rotunda before the casket of Sen. John McCain, R-Ariz., lies in state at the U.S. Capitol, Friday, Aug. 31, 2018, in Washington. Also pictured is Sen. Richard Shelby, R-Ala., right. Andrew Harnik/POOL Via REUTERS

Senator Richard Shelby (R-AL) points to an electrified rail as Senator Tim Scott (R-SC) steps across the track on the Senate subway in the U.S. Capitol in Washington, U.S., August 22, 2018. REUTERS/Joshua Roberts

Senator Richard Shelby (R-AL) speaks to reporters in the U.S. Capitol in Washington, U.S., August 22, 2018. REUTERS/Joshua Roberts

Senator Richard Shelby (R-AL) speaks to reporters in the U.S. Capitol in Washington, U.S., August 22, 2018. REUTERS/Joshua Roberts

Senator Richard Shelby (R-AL) speaks to reporters in the U.S. Capitol in Washington, U.S., August 22, 2018. REUTERS/Joshua Roberts

Sen. Richard Shelby (R-AL) speaks with reporters ahead of the weekly policy luncheons on Capitol Hill in Washington, U.S., July 24, 2018. REUTERS/Aaron P. Bernstein

U.S. Senator Richard Shelby leaves the Russia's Foreign Ministry building following a meeting with Foreign Minister Sergei Lavrov in Moscow, Russia July 3, 2018. REUTERS/Sergei Karpukhin

U.S. ambassador to Russia Jon Huntsman and U.S. Senator Richard Shelby get into a car following a meeting with Russian Foreign Minister Sergei Lavrov in Moscow, Russia July 3, 2018. REUTERS/Sergei Karpukhin

U.S. Senator Richard Shelby leaves the Russia's Foreign Ministry building following a meeting with Foreign Minister Sergei Lavrov in Moscow, Russia July 3, 2018. REUTERS/Sergei Karpukhin

Russian Foreign Minister Sergei Lavrov welcomes U.S. Senator Richard Shelby during a meeting with a delegation of U.S. lawmakers in Moscow, Russia July 3, 2018. REUTERS/Sergei Karpukhin

U.S. Senator Richard Shelby speaks during a meeting with Russian Foreign Minister Sergei Lavrov in Moscow, Russia July 3, 2018. REUTERS/Sergei Karpukhin

Senator Richard Shelby (R-AL) and Rep. Rodney Frelinghuysen (R-NJ) flank U.S. President Donald Trump as he speaks during a lunch meeting with Republican members of Congress at the White House in Washington, U.S., June 26, 2018. REUTERS/Kevin Lamarque

Senator Richard Shelby (R-AL) and Rep. Rodney Frelinghuysen (R-NJ) flank U.S. President Donald Trump as he speaks during a lunch meeting with Republican members of Congress at the White House in Washington, U.S., June 26, 2018. REUTERS/Kevin Lamarque

Senators Dick Durbin (L) and Richard Shelby (R) arrive before the Senate Appropriations Defense Subcommittee hearing on funding for the Department of Defense, on Capitol Hill in Washington, U.S., May 9, 2018. REUTERS/Yuri Gripas

Senator Richard Shelby (R-AL) speaks to reporters as he arrives for a nomination vote on Capitol Hill in Washington, U.S., December 13, 2017. REUTERS/Joshua Roberts

Sen. Richard Shelby speaks with reporters ahead of votes on Capitol Hill in Washington, U.S., December 6, 2017. REUTERS/Aaron P. Bernstein

Sen. Richard Shelby speaks with reporters ahead of votes on Capitol Hill in Washington, U.S., December 6, 2017. REUTERS/Aaron P. Bernstein

Sen. Richard Shelby (R-AL) speaks with reporters ahead of the party luncheons on Capitol Hill in Washington, U.S., October 3, 2017. REUTERS/Aaron P. Bernstein

President Donald Trump, accompanied by Sen. Richard Shelby (R-AL), arrives at Huntsville International Airport in Huntsville, Alabama, September 22, 2017. REUTERS/Aaron P. Bernstein

Senator Richard Shelby (R-AL) speaks to reporters ahead of the weekly party luncheons on Capitol Hill in Washington, U.S., August 1, 2017. REUTERS/Aaron P. Bernstein

Senate Majority Leader Mitch McConnnell, R, and Senator Richard Shelby, L, (R-AL) listen as U.S. President Donald Trump speaks during a meeting with Senate Republicans to discuss healthcare at the White House in Washington, U.S., July 19, 2017. REUTERS/Kevin Lamarque

Sen. Richard Shelby (R-AL) speaks with reporters about the Senate healthcare bill on Capitol Hill in Washington, D.C., U.S., June 27, 2017. REUTERS/Aaron P. Bernstein