Watching the two of them speak on the same topic in succession, Cruz’s decision to invite Trump to the rally starts to make more sense. Sure, he did it to endear himself to Trump’s voters, expecting that he’ll inherit them once Trump’s support starts to fade. Sure, he wanted a big media megaphone for this Iran rally and knew that Trump is the only candidate out there who could guarantee they’d show up. But he also knew that he’d benefit from the contrast: See for yourself how much more knowledgeable Cruz seems about the subject than Trump. Trump’s speech is nothing but the usual boastful applause lines about how we’ll have the classiest, most luxurious military ever with him as president and that he’ll out-negotiate the ayatollah so terrifically that it’ll make your head spin. Cruz’s speech is methodical, taking care to hit all the sore spots in U.S. relations with Iran — American hostages, the threat to Israel, and of course the idea that whether the deal is stopped depends not on Barack Obama or his Democratic sycophants in Congress but on his old nemeses, John Boehner and Mitch McConnell. Skip to 7:15 to see Cruz run through the argument I described in this post, that because Obama hasn’t submitted the secret side deals with Iran to Congress, the GOP should feel no obligation to vote on the deal anytime soon. That’s classic Cruz — he knows he’s going to lose this fight, and when he does he’ll have set up the face of the Republican establishment for blame. Exactly what a populist would-be president needs to draw voters.

Let’s go back to the point about Cruz inheriting Trump’s voters, though. I wondered in a post last week whether that assumption, which seems to be shared by nearly everyone, is true. Yeah, they’re the two showiest populists in the race, but their styles — and politics — are so different that it doesn’t necessarily follow that a Trump voter would look to Cruz if Trump quit tomorrow. Trump is a moderate Republican apart from immigration; Cruz is an across-the-board conservative. Trump is an outsider who’s never held public office; Cruz has been a senator for nearly three years. Trump is a billionaire who boasts that he won’t owe donors anything if he’s elected; Cruz has built one of the biggest war chests in the GOP field thanks in part to contributions from GOP fatcats. How likely is it that Trump fans are Cruz fans in the making? David Brady and Douglas Rivers studied the question and concluded that it may seem likely at first blush…

Looking at the numbers pre and post Trump’s announcement reveals that among May’s top five candidates, Paul, Walker and Bush lost 18, 17 and 11 percent, respectively, of their supporters to Trump, while Rubio lost 21 percent and Cruz an astonishing 47 percent to Trump. Among “leaning” Republicans, all candidates (save Rand Paul) hemorrhaged more than 20 percent to Trump, ranging from Walker’s 34 percent to Cruz’s 25 percent loss. Overall, among the top five back in May, Bush was hurt the least and Cruz the most, though all lost votes in the double digits to Trump.

…but when you dig deeper, you find it’s not that likely at all:

If the Trump campaign were to end, would his votes go back to the candidates from whence they came? We also asked people who their second choice for the nomination was, and the results for Trump voters are somewhat surprising. Only three candidates in the large Republican field get into double digits and just barely, at that. Ben Carson is the second choice for 13 percent of Trump backers, and Carly Fiorina is the choice of 10 percent. Jeb Bush is also the second choice of 10 percent of Trump voters—about the same proportion that abandoned him for Trump. After these three candidates, second choices are widely spread, with the exception of Jim Gilmore, Lindsey Graham, George Pataki, Jindal, and Perry at roughly zero percent or within error variance of zero. Sen. Cruz, who lost the most support to Trump, is the second choice of only 9 percent of Trump supporters.

The two other outsiders, Carson and Fiorina, and the most prominent moderate in the race, Jeb Bush, pick up more of Trump’s voters than the conservative populist insider-outsider Cruz does, at least according to this data. Another poll taken recently by Monmouth found, however, that Cruz was the second choice of 24 percent of Trump’s voters, tops among all candidates. Cruz’s campaign strategy of cuddling up to Trump is based on the theory that Monmouth is right and Brady and Rivers are wrong. I sure hope he’s right about that or else we might be staring at a “Carson versus Bush” race if Trumpmania ever cools. Gulp.