In 2011, former Illinois Gov. Rod Blagojevich was sentenced to 14 years in prison for his attempt to profit from the sale of Barack Obama’s old Senate seat. When President Trump commuted his sentence in February, Blagojevich naturally expressed his gratitude, calling himself a “Trumpocrat.”

To date, Blagojevich is the only former Democratic governor to endorse Trump. By contrast, Joe Biden has been endorsed by eight former Republican governors, including John Kasich of Ohio, Rick Snyder of Michigan and Tom Ridge of Pennsylvania. They haven’t minced words in deploring Trump, describing him variously as a “bully," “reprehensible” and “dangerous.”

“If a Republican President is incapable of condemning white supremacists, then the party of Lincoln has expired,” Ridge tweeted last week, following the first Trump-Biden debate.

The other former governors who’ve endorsed Biden are Christine Todd Whitman of New Jersey, Marc Racicot of Montana, Jim Edgar of Illinois, Arne Carlson of Minnesota and William Weld of Massachusetts. They are all part of a sizable group of former Republican officials who have come out for Biden, including former Cabinet secretaries, defense and foreign policy officials and two former chairs of the Republican National Committee.

Former President George H.W. Bush voted for Hillary Clinton in 2016 and it’s widely believed that his son will vote for Biden, although he won’t endorse anyone publicly. This many prominent GOP defections may simply be an expression of distaste for Trump personally, but it may also reflect a realignment in terms of party support, with more college-educated voters switching to the Democrats, even as Republicans increase their white working class support.

In past years, a single prominent cross-party endorsement could gain considerable attention, simply because it’s historically so rare. “I can’t recall nearly as many endorsements across party lines as we are seeing this year for Joe Biden — or rather, against Donald Trump,” said Thad Kousser, a political scientist at the University of California, San Diego.

As governor, Georgia Democrat Zell Miller gave the keynote speech at the 1992 Democratic National Convention. Twelve years later, then-Sen. Miller gave the keynote address at the Republican National Convention and campaigned for the younger Bush. Connecticut Sen. Joe Lieberman, the Democratic nominee for vice president in 2000, endorsed his Republican friend John McCain for president eight years later.

Crossing party lines is particularly striking at a time when members of the two major parties are often loath to collaborate on anything, let alone publicly support someone from the other side during elections. The U.S. Chamber of Commerce, a traditional GOP ally, has angered Trump and opened up divisions within its own ranks by endorsing about two dozen freshman House Democrats for re-election.

This year, Cindy McCain, the late senator’s widow, is supporting Biden. A group of alumni of George W. Bush’s administration have set up a political action committee to support Biden. Various other Republicans are backing Biden through groups such as The Lincoln Project and Republican Voters Against Trump.

Trump continues to enjoy overwhelming support among rank-and-file Republicans. A Gallup poll last month found that 94 percent of Republicans approve of the job he’s doing as president.

But some Republicans have their doubts and there are conservative voters who have stopped identifying with the party. The various former officials coming out for Biden are trying to send a signal to Republicans who may have soured on Trump that it’s okay to go all the way and cast a vote for a Democrat.

“I’m reaching out to the governors particularly as they come out, as it were, to be part of Republicans and Independents for Biden,” said Whitman, who served in George W. Bush’s cabinet. “These are respected opinion leaders who are telling people who won’t vote for Trump but don’t want to pull a lever for a Democrat that it’s okay to pull a lever for country over party.”

What’s Their Problem With Trump?

The governors breaking with Trump have faulted him for stances on various issues such as immigration and foreign policy. Most notably, several have criticized his response to the coronavirus pandemic.

Their knock on Trump, however, has mainly to do with character. They have described him as divisive and unwilling to learn.

“I was very apprehensive when he ran the first time,” said Edgar, the former Illinois governor. “I didn’t think he had the knowledge, the personality. After four years, he turned out to be far worse than I thought he might be.”

Edgar says this will be his first time in 50 years of voting that he hasn’t supported the Republican candidate for president. Like Whitman, he’s 74 and hasn’t run for office since the 1990s. Edgar is candid about the fact that it’s relatively easy for him to come out against a president of his own party, since he doesn’t have to worry about his own political future.

In fact, he says he’s advised sitting politicians not to break with Trump publicly.

“I said, ‘No, no, you’re running this year, you don’t want to get into that,’” Edgar said. “’You’ll send Republicans up the wall and you’ve got to win your own election.’”

But Edgar says former governors “speak with experience.” It’s notable that more former governors than senators have come out against Trump, although there are four former GOP senators who have endorsed Biden.

During the 1990s, Republican governors were viewed as more pragmatic than the party’s more ideological congressional wing, led back then by Newt Gingrich.

“The GOP came to the fork in the road and rejected the one their governors had taken and marched enthusiastically down the lane of ideology,” said Larry Sabato, who directs the University of Virginia Center for Politics. “Some of these governors are (politically) homeless, and they’ve decided to endorse Biden because they see him as far more pragmatic and moderate than Trump.”

Can They Convince Voters?

It’s hard to point to many endorsements that have swayed a discernible number of voters. Congressman Jim Clyburn’s embrace of Biden ahead of the South Carolina primary has been widely described as this year’s most important endorsement, but the state and its Black Democratic voters had been trending toward Biden anyway.

The effect of support even from sitting governors on presidential voting in their states is sometimes overblown, but endorsements from former governors from swing states, such as Ridge and Snyder, matter if only because they’ve drawn some local media attention.

On Tuesday, Puerto Rico Gov. Wanda Vázquez endorsed Trump for re-election. She’s a Republican, but her stance may help inoculate Trump from some criticism over his handling of Hurricane Maria, which matters not only on the island but also among Puerto Rican voters in Florida.

Endorsements can matter at the margins, says Sam Rosenfeld, a political scientist at Colgate University. Voters who aren’t following a race carefully might turn to politicians they respect for guidance and cues. “I think it matters that Kasich is giving room to lifelong Republicans in all these suburbs so they can comfortably say to themselves, this is not our party anymore,” Rosenfeld said.

Rather than individual endorsements, the sight of lots of political insiders or celebrities rallying behind a candidate sends a strong signal to voters about which way people like them might be leaning. “In our theory, party insiders rally to the candidate of their choice, endowing him or her with endorsements, access to fund-raising networks, and pools of talent and volunteer labor,” wrote the authors of The Party Decides, a widely cited book about the influence of party support on presidential primaries.

Whitman says she’s received both attacks for breaking with the party and thanks from people who are grateful she’s taking such an active stance. She says more Republicans who complain about Trump in private need to speak up publicly.

“He’s not a Republican,” she said. “He hasn’t shown a concern for the basic values that used to be our Republican values.”