Another notable leftover from yesterday via Mediaite. I didn’t understand Trump’s answer the first time I watched but I get it now: He thinks Tapper, who mentions Rubio in his question, is asking him specifically about Republican candidates refusing to support him in the fall. In that case, turnabout’s fair play. If Rubio breaks his pledge now, which he kinda sorta already has, then Trump will break his pledge if he ends up losing the nomination to Rubio and the defeat of the GOP in the general election is assured. There’s no doubt in my mind that a Trumpist third party would siphon off more votes from the Republican nominee than a conservative third party would siphon off from Trump if he’s the Republican nominee. What Trump’s saying here, in so many words, is that if Rubio’s serious about breaking his pledge than the presidential race is effectively over for conservatives. Either Rubio comes back to win the nomination and is destroyed by Hillary when 20 percent of the party votes Trump or Rubio fails to come back and conservatives enter the general election effectively sidelined after having declared war on Trump in the primary and lost. Your best bet is to honor the pledge, line up behind Trump against Hillary, and … hope, I guess, that he’s conservative-ish as president.

But that’s not really what Tapper’s asking him. He’s using Rubio as an example of the broader #NeverTrump sentiment being circulated by grassroots conservatives on social media. These people are claiming they’re not going to vote for you, Tapper’s saying. What can or will you do to change that? Trump retaliating by running third-party is obviously no deterrent to voters who are themselves prepared to go third-party to avoid voting for him. Nothing would please them more than for Trump to quit the GOP now and go do his own thing. That would guarantee defeat this fall, but NeverTrumpers have already accepted that as the price of stopping him. As one former Romney advisor put it:

“For many Republicans, Trump is more than just a political choice,” said Kevin Madden, a veteran operative who advised 2012 nominee Mitt Romney. “It’s a litmus test for character.”

Madden, like some of his peers, said he could never vote for Trump. If he is the nominee, Madden said, “I’m prepared to write somebody in so that I have a clear conscience.”

Correct, and voters who think that way will not easily be converted. Essentially, Tapper’s inviting Trump to pander to conservatives and reassure them that he’ll appoint new Scalias to the bench and so on. Instead, it’s just more threats. Not gonna get people to hold their noses and pull the lever that way, pal.

Do conservative NeverTrumpers have the numbers to stop him this fall? If a third party gets going I think it could attract somewhere between 10-15 percent in early polls this summer. But as the sheer stench from the Clintons overwhelms the right, some sizable part of that will fall away and stick with Trump. You’re looking at maybe seven or eight percent who balk on election day. That’s enough to sink him in a close race, but that assumes Trump doesn’t add to his coalition by pulling in centrist Democrats and inspiring people who haven’t voted in years to register and turn out. I think it’s possible he wins even with the rump of the conservative movement in rejectionist mode. But a fractured party in the primary usually doesn’t point to victory in the general, per Nate Silver:

In 1972, for instance, about a third of Democrats voted for Richard Nixon rather than George McGovern, who won the Democratic nomination despite getting only about a quarter of the popular vote during the primaries. The Democrats’ tumultuous nomination process in 1968 was nearly as bad, with many defections to both Nixon and George Wallace. The 1964 Republican nomination of Barry Goldwater produced quite a few defections. Primary challenges to Jimmy Carter in 1980 and George H.W. Bush in 1992 presaged high levels of inter-party voting in November.

There are also some exceptions; Republicans remained relatively united behind Gerald Ford in 1976 despite a primary challenge from Ronald Reagan. And there were high levels of Democratic unity behind Obama in 2008, although one can argue that a party having two good choices is a much lesser problem than it having none it can agree upon.

Overall, however, the degree of party unity during the primaries is one of the better historical predictors of the November outcome. That could be a problem for Republicans whether they nominate Trump or turn around and nominate Marco Rubio, Ted Cruz or John Kasich; significant numbers of GOP voters are likely to be angry either way.

The last part is key. The argument here isn’t that the GOP necessarily loses unless it nominates someone besides Trump. The argument is that the GOP is likely (but not certain) to lose regardless of who it nominates at this point because Trump and Rubio are each deeply unacceptable to different wings of the party. Adrian Gray snatched this data from CNN’s new national poll today showing Trump ahead of Rubio and Cruz by more than 30 points nationally. The good news for Trump fans: Republicans are no more likely to say they’ll stay home for Trump than they are for his two competitors. The bad news: They’re more likely to say they’ll stay home than they’ve been in years past.

Divided Party: % of GOP supporting nominee in November (CNN Poll)
w/ Trump: 76
w/ Cruz: 75
w/ Rubio: 74
(was 93 in 2012, 90 in 2008)

— Adrian Gray (@adrian_gray) February 29, 2016

If you dig into the crosstabs, you’ll find a disparity between Rubio and Cruz on the one hand and Trump on the other. Sixty-nine percent of Republicans who aren’t supporting Rubio say they’d definitely or probably vote for him as nominee; the same percentage say so of Cruz. Just 52 percent of GOPers who aren’t voting for Trump say they’d get onboard the Trump train, though; 13 percent say they probably wouldn’t support him and another 35 percent say they definitely wouldn’t. If those last numbers held, you’d have nearly 18 percent of the total Republican electorate boycotting Trump on election day. Hillary would need to screw up awfully badly to lose an advantage like that. But if anyone can do it, she can!