Here's the conundrum for the 'Never Trump' movement

Republican U.S. presidential candidate Donald Trump holds up a CNN poll of voters nationally, showing him in the lead, while addressing a campaign rally in Portland, Maine March 3, 2016.
Joel Page | Reuters

The Catch-22 of Republican opposition to Donald Trump was laid bare in the final moments of the latest debate, when co-moderator Chris Wallace asked the candidates about their previous pledge to support the party nominee.

Following a two-hour indictment of Trump's basic integrity, sanity and honesty, with his rivals describing a Trump presidency in the terms of a global catastrophe, Marco Rubio, John Kasich and Ted Cruz nonetheless said they would support him if he won the nomination.

It was a whimpering comedown for a day that was supposed to mark the opportune moment of the "Never Trump" movement, which began with the unprecedented action of the party's past nominee, Mitt Romney, taking to a podium to vilify his near-sure successor.

In a "State of the Race" speech at the Hinckley Institute of Politics in Salt Lake City, Romney called Trump a "phony," and warned Americans that his election could imperil the nation's economy and national defense. And yet, it stopped well short of a denouement.

To New York magazine's Jonathan Chait, the speech typified the fundamental problem of the GOP anti-Trump revolt: "Full of righteous rage, but confused about how to proceed and unwilling to follow its own analysis through to its conclusion."

That unwillingness was only further ratified at the debate.

Whether Trump's GOP opponents keep to their pledge remains to be seen — the term "flexible" got bandied about quite frequently during Thursday night's Fox News debate — but one thing is clear: Trump might not need to build any more reinforcements to his political wall if his Republican opposition can't get off the fence.

Joining Romney, Sen. John McCain, whose Vietnam War service was mocked by Trump, likewise issued his own dire warning to Republican voters about the front-runner. But shortly thereafter, a McCain spokesman suggested to Politico that the senator would still support the billionaire in a general election.

And so a presidential race that has so far redefined the idea of American politics, public decorum, and Republicanism, is threatening to redefine the definition of the word "never."

If the ultimate goal is to keep Trump away from the nuclear codes, as Never Trump proponents insist, they will likely have to confront a lesser-of-two-evils choice of supporting Hillary Clinton in November.

It's a realpolitik scenario CNBC.com put to some of Trump's most devoted dissidents, who seem disinclined to take the oppositionist crusade to its inflection point — a vote for Clinton.

"For me, I haven't put a checklist of pro versus con," said Doug Heye, a veteran GOP strategist who was among the early Trump declaimers, when asked to say who would be worse, Clinton or Trump. "I think they are both terrible directions."

Heye holds out hope that a viable write-in conservative candidate will manifest, allowing him to vote for a non-Trump Republican without having to engage in voting-booth game theory.

"The extremities we would see, if Trump is our nominee, I think make it very easy to find a constitutional conservative to vote for," said Heye. "I think we could be at a place were, in November, if Trump is our nominee, voting for Trump is symbolic because he can't win."

The prospects of a mainstream Republican running on a third-party ticket — with names like Romney, rising-star Nebraska Sen. Ben Sasse, and House Speaker Paul Ryan — have been floated in recent weeks, but with little optimism. Moreover, such a candidacy would risk only further splintering the party and the conservative movement.

For now, the best the phalanx can do is to sit astride the anti-Trump fence.

When asked about voting for Clinton if all else fails, Katie Packer, the former Romney aide now leading the anti-Trump Our Principles super PAC, told CNBC.com: "I don't have an opinion at this point. … We feel like we have a path to prevent him and a way to prevent him, and a way to prevent him is for somebody else to get the nomination. There is a whole lot more game to be played before we even get to what you are talking about."

According to various news reports this week, certain anti-Trump GOP factions are trying to wrest the nomination from Trump with a floor fight at the Republican National Convention. But on Thursday, RNC Chairman Reince Priebus sought to douse any notion of a delegate insurrection, telling CNN the party would avoid "shell games." And even Republican Sen. Lindsey Graham, a strong Trump adversary, said a brokered convention would be unfair.

Former Rep. Bob Inglis, a moderate Republican from South Carolina, said he thought many of his former colleagues would prefer Clinton, even if their support will remain tacit.

"We've got to hope Hillary wins the nomination because at least it prevents the worst-case scenario, which is Trump beating Bernie Sanders in a landslide," Inglis told CNBC.com. "It is a very difficult position to be in: You don't support Hillary, incumbent Republicans do not support Hillary, but they are sane, and they want sane people in government."

We've got to hope Hillary wins the nomination because at least it prevents the worst-case scenario, which is Trump beating Bernie Sanders in a landslide.
Former Rep. Bob Inglis, moderate Republican

Come Friday evening, attention will turn to former candidate Carly Fiorina, who is slated to give a keynote address at the Conservative Political Action Conference in Washington. Fiorina has been silent since dropping out of the race last month, but she was a notable target of Trump's misogyny on the trail. Fiorina's deputy campaign manager, Sarah Isgur Flores, announced earlier this week that she would not support Trump if he becomes the nominee, but neither would she commit to voting for Clinton as the lesser evil.

Fiery GOP debate sparks insults, attacks and taunts

"Gaming out one's vote is a mistake," she said. "I think you should vote for the person you believe should be president."

Florida GOP strategist Rick Wilson, the sharp-tongued bard of the Never Trump brigade, mustered at least a modicum of comparative credit for Clinton.

"I will phrase it this way: Hillary has the benefit of at least not being clinically insane," he told CNBC.com, but added that that still wouldn't ever be enough to vote for her.