After House Speaker Paul Ryan said Tuesday that he would not seek the presidency in 2016 under any circumstances, Scott Lemieux at Lawyers, Guns and Money issued a challenge to those who think someone besides Donald Trump or Ted Cruz could be the Republicans’ nominee:

Anybody who thinks this is a plausible scenario really needs to explain specifically how this is going to work.

I think it is plausible and I can explain why. It’s a good excuse to run through the remaining possibilities on the Republican side.

True, a victory by a third candidate isn’t the most likely outcome. It’s still possible Trump will have enough bound and committed delegates to win in the first round. It’s even more likely that Ted Cruz will gather enough loyal delegates to reach the magic number of 1,237 (though many of them haven’t been chosen yet).

But remember: In many states the allocation of delegates — to a candidate they are initially bound to vote for, based on the primaries and caucuses — is different from the selection of the individual people who will become delegates. The numbers we’re hearing about now are about allocation and tell us what will happen on the first ballot. If no one wins at that point, however, things change.

Most delegates will be free to vote their personal choice after the first (or for some states the second) ballot at the party’s convention. So if no one gets the required votes on the first ballot, what matters is what the delegates want, not what they are currently bound to do. By all accounts, Trump is far behind in the delegate selection game. Few of the uncommitted delegates will support him, and even some of those who are required to vote for him on the first ballot may oppose him.

If we get to the point where the delegates are unbound, the convention will be split among three groups.

First, there will still be a large bloc of Trump die-hards. It’s hard to imagine Trump making a deal that doesn’t wind up with him as the GOP nominee (since it’s hard to see what else he might want from the party), so his loyalists will likely keep voting for him or walk out.

Then there will be the solid Cruz people. Most of his bound delegates and some others will be in this camp, although others might simply be from the Cruz faction of the party, and open to candidates similar to him if other names are suddenly in play in a later stage at the convention.

The third bloc of delegates isn’t a bloc at all. Some will have been bound to John Kasich or even Marco Rubio. (The Florida senator is retaining the 172 delegates he won before dropping out.) Others will be “party” people who were chosen as delegates originally bound to Trump (or to one of the other candidates). Who they are, and what they care about, will vary from state to state.

Some “party” people might be moderates who care more about winning in November than in ideological purity or in an individual candidate. Some others might be Christian conservatives or Tea Partyers or libertarians who have taken over their local parties, recently or years ago, and secured the delegate slots by dominating their state’s selection process. The only thing they are likely to have in common is opposition to Trump, and reluctance to support Cruz. 

This third group of delegates doesn’t have to vote for Cruz at the convention to stop Trump. They can vote for Kasich, Rubio or Mickey Mouse for that matter. If the 2012 Republican rules and precedents remain the same, their votes will not be formally recorded, but they will count as numbers withheld from Trump or Cruz in the two men’s quest to hit the 1,237 target.

Lemieux and Jonathan Chait believe that careful coordination among the anti-Trump and anti-Cruz delegates will be necessary for the convention to wind up turning to a third candidate. But this coordination isn’t needed to produce a stalemate. All that will take is for enough delegates who don’t want Trump or Cruz to stubbornly refuse to vote for either.

And the likely sequence of events will make it easier for them to be stubborn.

Trump almost certainly has to win on the first ballot, when almost all delegates are still required to vote as allocated by the primaries and caucuses, or not at all. In fact, we’re likely to know by the final primaries on June 7, or at least early in the weeks before the convention, if Trump has enough votes or not.

If he doesn’t win on the first ballot, and if Cruz can’t muster 1,237 delegates who want him to be the nominee, the convention will deadlock. The only other option is to find a third candidate. It would have to be one the Cruz contingent would be willing to accept, and therefore a very conservative candidate. It could not be a relative moderate such as Mitt Romney or John Kasich.

How likely is all of this? We don’t know yet. We don’t know how many Trump-bound delegates will stick by him. We don’t know how many Trump delegates might be loyal to Cruz. Nor do we know whom the Rubio and Kasich delegates would favor.

An organized effort to dump both Trump and Cruz ahead of the convention won’t work. But turning to a third candidate to break a deadlock, while unlikely, is plausible.

By Jonathan Bernstein

Jonathan Bernstein is a Bloomberg View columnist covering U.S. politics. A political scientist, he previously wrote “A Plain Blog About Politics.” He is coeditor of “The Making of the Presidential Candidates 2012.” — Ed.

(Bloomberg)