So let's talk about the Republicans instead.
Last week, Mitt Romney delivered a speech blasting Donald Trump and calling for Republicans to deny him the 2016 presidential nomination. Romney declined to endorse a specific alternative candidate, instead advocating a kind of strategic-voting scheme in which Republican voters supported the strongest non-Trump aspirant in their specific state primaries and caucuses. "Given the current delegate selection process," said Romney, "that means that I’d vote for Marco Rubio in Florida and for John Kasich in Ohio and for Ted Cruz or whichever one of the other two contenders has the best chance of beating Mr. Trump in a given state."
At least for Romney, and presumably for many other anti-Trump Republicans (who have adopted the hashtag #NeverTrump on Twitter to identify themselves), the goal is not to defeat Trump outright in the primaries by delivering a delegate majority to a single rival candidate. Instead, they hope that a robust multi-candidate field denies Trump a majority of his own, preventing him from winning a first-ballot victory at the Republican national convention in Cleveland. Then, the thinking goes, an agreement can be worked out among the non-Trump candidates and their delegates to nominate a superior compromise candidate, perhaps a widely-acceptable Republican who didn't run in the primaries this year. Maybe even someone like Mitt Romney.
This plan contains one obvious concession to reality: the delegate math at this stage makes it very difficult for any candidate other than Trump to gain an outright majority via the primary process, and a multi-candidate field of opposition may well do a better job than a single rival at holding Trump under the needed 1,237 delegates. But it still seems to rely on an awful lot of wishful thinking, politically speaking. Frankly, it's very hard to see exactly how it's supposed to work.
First, it will be very difficult for Republican leaders to explain to the American public why Trump should be denied the nomination if he wins the most states, votes, and delegates of all the candidates. If he falls short of an overall majority, of course, he would not be automatically recognized by the party itself as its official nominee, but he would still be widely seen by the citizenry as having the most legitimate claim to the prize—especially in comparison to someone like Romney or Paul Ryan who didn't even face the voters this year.
Second, any stop-Trump effort at the convention will need to reckon with Ted Cruz, who has pulled into a clear second-place position in the nomination contest. Between them, Trump and Cruz have won 63 percent of the popular vote and 77 percent of the delegates awarded so far—and both proportions may well increase between now and the end of the process, as winner-take-all primaries become more prevalent and also-ran candidates drop out of the race. It's a safe bet that the Trump and Cruz factions will together constitute a majority, and probably a supermajority, of the Republican convention delegates.
With this in mind, it's worth considering why it would be in Cruz's personal or political interest to be party to any move to deny the nomination to a plurality-winning Trump campaign. Of course, Cruz might be potentially amenable to an agreement that made him the nominee instead—though such a deal seems unlikely, given Republican leaders' personal antipathy toward Cruz and widespread view of him as a weak general-election candidate. But a senator who has already burned most of his bridges in Washington and who has carefully cultivated a public reputation as a principled foe of the Republican leadership also has no obvious reason to help that leadership stop Trump via a procedural maneuver that will be inevitably criticized as democratically illegitimate by a large segment of the party's popular base.
Under the circumstances, Cruz might well be better served by throwing his support to Trump as the acknowledged popular choice of the party electorate than by allying with other candidates to block him. If Trump were to become president, Cruz would then be in a position to enjoy considerable influence within the Republican Party; in the much more likely scenario of a Trump defeat, Cruz could run for the presidency again in 2020 with his anti-Washington credentials intact, appealing to purist conservatives and ex-Trump supporters alike.
It is thus unsurprising that Cruz himself has publicly disavowed the idea of playing for a contested convention. As he told CPAC this weekend, “Any time you hear someone talking about a brokered convention, it is the Washington establishment in a fevered frenzy. They’re really frustrated because all of their chosen candidates, all of the golden children, the voters keep rejecting. And so they’ve seized on this master plan: we go to a brokered convention and the D.C. power brokers will drop someone in who is exactly to the liking of the Washington establishment. If that would happen, we will have a manifest revolt on our hands all across this country.”
It is thus unsurprising that Cruz himself has publicly disavowed the idea of playing for a contested convention. As he told CPAC this weekend, “Any time you hear someone talking about a brokered convention, it is the Washington establishment in a fevered frenzy. They’re really frustrated because all of their chosen candidates, all of the golden children, the voters keep rejecting. And so they’ve seized on this master plan: we go to a brokered convention and the D.C. power brokers will drop someone in who is exactly to the liking of the Washington establishment. If that would happen, we will have a manifest revolt on our hands all across this country.”
These remarks did not appear to receive much attention in the press, but they indicate that the anti-Trump movement—which, to be accurate, is in some respects an anti-Trump-and-Cruz movement—faces odds of success that are quite long indeed. (They also suggest that Cruz may still maintain hopes of gaining a delegate plurality himself, in which case he would obviously demand the nomination as the choice of the Republican electorate.) Republicans might conceivably block Trump by quickly rallying around Cruz, though there seems to be little enthusiasm for doing so—and those who find neither candidate acceptable are unlikely to get their way in Cleveland.