From the insular political system to the naysaying media culture, Donald Trump essentially clinching the Republican nomination is a stunning development, especially the swiftness with which his two remaining rivals gave up.

But for the anti-Trump folks, it is sheer torture.

In the wake of an Indiana victory that drove Ted Cruz and John Kasich from the race, they are left with a series of unpalatable choices that will have an impact on fall campaign—and on the GOP’s future.

Some are already declaring themselves to be in the #NeverNeverEverTrump camp. They will oppose the billionaire up to and until he raises his hand over the Bible next January.

In doing so, of course, they will tilt the election toward Hillary Clinton. But the diehards are willing to accept another four years out of power as a reasonable price to pay for blocking Trump.

Trump, for his part, says he doesn’t want or need the support of everyone in the party. The truth is—and this is hard for his detractors to accept—he is remaking the party in his own image. Trump is not a doctrinaire conservative, and for the moment, he is the face of the GOP.

George Will, the syndicated columnist and Fox News contributor, casts the choice as a moral test:

“Donald Trump’s damage to the Republican Party, although already extensive, has barely begun. Republican quislings will multiply, slinking into support of the most anti-conservative presidential aspirant in their party’s history. These collaborationists will render themselves ineligible to participate in the party’s reconstruction.”

Trump fired back on “Morning Joe”: “Well, George is a major loser. You know, he’s a dour guy. Nobody watches him. Very few people listen to him. It’s over for him, and I never want his support.”

Steve Hayes, the Weekly Standard writer and Fox News contributor, quickly posted a piece titled “No Trump”:

“Trump's claim to be a unifier is not just specious, it's absurd. This casual dishonesty is a feature of his campaign. And it's one of many reasons so many Republicans and conservatives oppose Trump and will never support his candidacy. I'm one of them.”

Another Fox contributor, Townhall’s Guy Benson, tweeted: “Much to my deep chagrin (& astonishment ~8 months ago), for the 1st time in my life, I will not support the GOP nominee for president.”

Influential blogger Erick Erickson tweeted: “Reporters writing about the ‘Stop Trump’ effort get it wrong. It's ‘Never Trump’ as in come hell or high water we will never vote for Trump.”

The Daily Caller’s Jamie Weinstein: “There is just no question: I’d take a Tums and cast my ballot for Hillary — and I suspect so would many other life-long conservatives, whether they are willing to admit it now or not.”

There is a camp within this camp, led by the Standard’s Bill Kristol, that is actively encouraging a conservative third-party run. This would undoubtedly hand Hillary the keys to the White House. There is a fantasy that somehow it would throw the election into the House. But the Wall Street Journal editorial page, hardly a fan of Trump, calls this a truly bad idea.

An even smaller subset is finding Clinton, who is more hawkish than Trump, a better alternative. These include Mark Salter, once John McCain’s top strategist.

But there are other conservatives who are softening on Trump, saying that perhaps he wouldn’t be that bad. Some are acting out of party loyalty. Some want to clamber onto the winner's bandwagon (even after saying incredibly harsh things about him, according to Trump). Some think Clinton would be far worse. And some may be looking for jobs or contracts. I suspect this group will grow in size.

Here’s the bottom line for those on the right who still oppose Trump: How do they explain that he won one state after another, in some cases every county, before sweeping to seven straight victories? How do they explain that he beat 16 other senators and governors and assorted luminaries? How do they explain that his vision of conservatism proved more popular than theirs with Republican voters?

Maybe Trump’s critics are right that he will lead the party to a major defeat. The question now is how many will work toward that outcome.

Howard Kurtz is a Fox News analyst and the host of "MediaBuzz" (Sundays 11 a.m. and 5 p.m. ET). He is the author of five books and is based in Washington. Follow him at @HowardKurtz. Click here for more information on Howard Kurtz.