Democratic 2020 presidential candidate and Senator Elizabeth Warren is joined onstage by her husband Bruce and their dog Bailey at a rally in Cedar Rapids, Iowa, February 1, 2020. Bailey, a golden retriever, was a popular surrogate for his owner on the campaign trail.

REUTERS/Brian Snyder

Bailey attends a rally with supporters in Des Moines, Iowa, January 31, 2020. During President Donald Trump's Senate impeachment trial, Warren was unable to campaign before the Iowa caucuses, and sent in her husband Bruce Mann and Bailey. "Bailey arrived in Iowa late on Friday. In 24 hours, the Des Moines Register had endorsed Elizabeth ... The dog's a natural closer," Mann joked.

REUTERS/Brian Snyder

Elizabeth Warren, her husband Bruce and their dog Bailey leave their house to vote on Super Tuesday in Cambridge, Massachusetts, March 3, 2020. REUTERS/Brian Snyder

A supporter of Elizabeth Warren pets her dog Bailey, in Carroll, Iowa, January 30, 2020. REUTERS/Brian Snyder

Elizabeth Warren, with her husband Bruce and their dog Bailey, greets resident Lucien Trudeau (R) while campaigning door-to-door in Manchester, New Hampshire, February 8, 2020. REUTERS/Brian Snyder

An attendee leaves a campaign town hall event held by Elizabeth Warren near a large inflatable version of Warren's dog, Bailey, at the Clark County Government Center Amphitheater in Las Vegas, Nevada, February 21, 2020. REUTERS/David Ryder

Elizabeth Warren, her husband Bruce and their dog Bailey arrive for a campaign town hall meeting at Dartmouth College in Hanover, New Hampshire, October 24, 2019. REUTERS/Brian Snyder

Elizabeth Warren pets her dog Bailey at a campaign canvass kickoff at the home of a supporter in Urbandale, Iowa, February 1, 2020. REUTERS/Brian Snyder

Elizabeth Warren is joined onstage by her husband Bruce and their dog Bailey at a rally in Cedar Rapids, Iowa, February 1, 2020. REUTERS/Brian Snyder

Elizabeth Warren, accompanied by her husband Bruce and their dog Bailey, campaigns door-door with volunteer Colin Pio (C) in Manchester, New Hampshire, February 8, 2020. REUTERS/Brian Snyder

Elizabeth Warren waits to take the stage with her husband Bruce and their dog Bailey at a campaign stop in Exeter, New Hampshire, March 15, 2019. REUTERS/Brian Snyder

Bailey is seen outside the Democratic presidential debate at Saint Anselm College in Manchester, New Hampshire, February 7, 2020. REUTERS/Eric Thayer

Elizabeth Warren’s husband Bruce, with their dog Bailey, speaks to supporters in Carroll, Iowa, January 30, 2020. REUTERS/Brian Snyder

Elizabeth Warren pets her dog Bailey after a campaign event in Cedar Rapids, Iowa, February 1, 2020. REUTERS/Rick Wilking

Elizabeth Warren is joined by her dog Bailey while speaking to New Hampshire Young Democrats in Nashua, New Hampshire, February 23, 2019. REUTERS/Brian Snyder

Elizabeth Warren is joined onstage by her husband Bruce and their dog Bailey at a rally to launch her presidential campaign in Lawrence, Massachusetts, February 9, 2019. REUTERS/Brian Snyder

Elizabeth Warren is joined by her dog Bailey at a campaign town hall meeting at Dartmouth College in Hanover, New Hampshire, October 24, 2019. REUTERS/Brian Snyder

Elizabeth Warren is joined onstage by her husband Bruce and their dog Bailey at an organizing event in Manchester, New Hampshire, January 12, 2019. REUTERS/Brian Snyder