Former U.S. Rep. Jim Greenwood has worked in Republican politics for almost five decades, supporting his party’s presidential candidates from Richard Nixon to Mitt Romney.

Then came President Donald Trump.

Greenwood, a self-described “Never Trumper,” said he helped set in motion a recruitment effort that began months ago and culminated Monday with endorsements for former Vice President Joe Biden by 27 former Republican members of Congress — three senators and 24 representatives from 18 states.

The Democratic nominee’s launch of Republicans for Biden took flight on the first day of the Republican National Convention, where Trump is expected to deliver prime-time speeches four nights in a row.

Greenwood, who served six terms in his Bucks County-based district before resigning in 2004, described Trump as a “small-minded, uncaring, self-aggrandizing compulsive liar” who has divided the nation.

“He was never qualified to do the job,” Greenwood said. “In my mind, he’s not emotionally healthy enough to be anywhere near the job of president.”

Former U.S. Rep. Charlie Dent, another Trump critic who now is a CNN commentator, said the president’s public embrace this month of a Republican candidate for the U.S. House in Georgia who subscribes to the QAnon conspiracy theory motivated him to endorse Biden.

“There was a time 10 years ago, if someone like this had popped up, they would have been ridiculed, mocked, and driven out of the party,” said Dent, a Republican who served seven terms in his Allentown-based district before resigning in 2018. “The president is now empowering people on the fringe.”

While many leading Republican figures said in 2016 that they couldn’t vote for Trump, few went as far as backing his Democratic opponent. That has changed this time. Dent wrote in independent candidate Evan McMullin in 2016 rather than voting for Hillary Clinton.

Former U.S. Rep. Bill Clinger, who served nine terms in his north-central Pennsylvania district from 1979 to 1997, also signed on to the Biden endorsement Monday. Clinger was one of 30 former Republican lawmakers who issued a letter critical of Trump one month before the 2016 presidential election, calling him “manifestly unqualified to be president.”

Biden’s campaign cast the Republican endorsements Monday as a “strong rebuke” to Trump, driven by the president’s “corruption, destruction of democracy, blatant disregard for moral decency, and the urgent need to get the country back on course.”

The Trump campaign didn’t immediately comment Monday.