Is the GOP Breaking Up Over Trump? Hank Paulson and George Will have expressed their unhappiness with Trump.

 -- The decisions by a number of well-known Republicans to buck the party because of Donald Trump's likely ascension to the top of the ticket could be seen as an effort to help rebuild the party, some experts say.

Longtime conservative and political columnist George Will said he recently changed his voter registration from Republican to unaffiliated.

Former Treasury Secretary Hank Paulson, a Republican who served under President George W. Bush, wrote in an op-ed in The Washington Post why a Trump presidency would be bad for the country, declaring that he will be voting for Hillary Clinton this fall.

And Brent Scowcroft, who was the national security adviser to Republican Presidents Gerald Ford and George H.W. Bush, put out a statement supporting Clinton and her "wisdom and experience." He did not mention Trump by name.

The "never Trump" movement gathered steam during the primaries, and there are some elected officials who say they support the idea. The recent announcements by party elders could signal a larger rebuke of Trump's campaign.

Hans Noel, an associate professor at Georgetown University, said longtime party members "don't think [Trump] is going to win, so they don't need to back him."

Referring to Will and Paulson, Noel said, "Their careers are winding down. So they just care about their legacy. They are jumping on the bandwagon now because Trump's poor performance is making it relevant."

Noel said these developments in the GOP mean that the party "is thinking ahead to life after Trump. And I think if Trump loses big, then the rebuilding task is easier."

James Campbell, a professor of political science at the University at Buffalo who has written a book about political polarization, said many Republicans view the November election as a lose-lose proposition.

"If Hillary wins, they and the nation loses," he said. "In the unlikely event that Trump wins, the nation loses, and the party is saddled with Trump into the future."

Zorine Bhappu Shirley, who served as a regional finance director for the Republican National Committee in the 1980s and the director of the Conservative Political Action Conference in the 1990s, said discontent among Republicans has been growing in recent years.

"Over the years, we have become a bigger-government party — higher taxes, bailouts and corruption, all these things that run contrary to what I believe a Republican believes in," she told ABC News.

"I don't know if we continue in that direction, if we can heal this and unify the party," she said.

That said, she is still supporting Trump's bid for the White House.

"I feel as if I have more faith that Trump will do what is right, knowing that Hillary will do everything that I am against," Shirley said.

Campbell warned that if Trump and his policies end up being viewed as the Republican establishment, that could be a "recipe for political failure."

"I think it is not too early to start the recriminations for the Trump fiasco. The establishment ignored the tea party by ramming through [John] McCain and [Mitt] Romney, and now the tea party folks are openly at war with their own party's establishment," Campbell said.

"Someone has to figure out a way to bring the party together. I am not convinced that leaving the party is a productive route to doing this," he said.