Among the big stories of the 2020 presidential campaign has been whether there will Republican defections to Joe Biden's campaign. He notably has the support of The Lincoln Project, a political action committee formed by many prominent Republicans.

On Tuesday, Cindy McCain, the widow of Arizona Senator and 2008 Republican presidential nominee John McCain, formally endorsed the Democratic nominee. She praised Biden’s personal character and said she believes he will lead the country with dignity.

“My husband John lived by a code: country first. We are Republicans, yes, but Americans foremost. There's only one candidate in this race who stands up for our values as a nation, and that is @JoeBiden,” McCain tweeted.

“Joe and I don't always agree on the issues, and I know he and John certainly had some passionate arguments, but he is a good and honest man. He will lead us with dignity,” she continued. “He will be a commander in chief that the finest fighting force in the history of the world can depend on, because he knows what it is like to send a child off to fight.”

Biden had told donors in an online fundraiser earlier in the day that Cindy McCain would endorse his campaign. Biden said she made the decision after The Atlantic reported that President Donald Trump called fallen soldiers “losers” and “suckers.”

Cindy McCain previously spoke about the friendship between her husband and Biden in a recorded video during the Democratic National Convention (DNC) this year. McCain’s daughter, Meghan McCain, has also signaled she may vote for Biden in this year’s election.

Trump has repeatedly disparaged John McCain. In 2015, Trump said that John McCain was not a war hero because he was captured, stirring outrage. Trump has also referred to him as a “dummy.”

A naval hero, John McCain was held as a prisoner of war in North Vietnam from 1967 to 1973 after his plane was shot down. He was tortured by his captors, suffering injuries for the rest of his life.

John McCain died of brain cancer complications in August 2018. Trump was not invited to his funeral.

Aside from The Lincoln Project, there have been many other prominent Republicans to endorse Biden. Former Ohio Gov. John Kasich, former Michigan Gov. Rick Snyder and former Secretary of State Colin Powell have all voiced their support for Biden. There has also been the Super PAC 43 Alumni for Biden, which includes administration and campaign officials of former President George W. Bush.