Via NRO, the key bit comes at 1:22. I think what he says is half true: Establishmentarians are “lining up behind Trump,” as Cruz claims, only if you accept Cruz’s self-serving premise that this is already a two-man race and he’s the sole alternative to Trumpmania. Rubio doesn’t accept it. In reality, the GOP leadership and most Republicans in Congress would probably prefer any Republican candidate except Cruz to Trump, starting with Jeb Bush and Rubio himself and on downward to Kasich, Christie, and the rest. The reason Rubio seems to be giving Trump some political cover here is because he thinks he still has more to fear from Cruz than Trump, both in New Hampshire and beyond. If Trump wins Iowa and New Hampshire but Rubio finishes a strong second in NH, that’s just fine. Cruz will have been effectively vanquished and Rubio will zoom into South Carolina as the only non-Trump game in town. Rightly or wrongly, every man in the field (starting with Jeb) thinks he’ll beat Trump head-to-head in a long race on the theory that the 65 percent or so of Republicans who aren’t supporting Trump right now have already made up their minds against him and will accept any alternative. So Rubio’s trying to do here to Cruz what Cruz has been doing to him — kill him early by blunting Cruz’s populist talking points against Trump. The truth, says Rubio (in so many words), is that Ted Cruz is a snake, a guy who puts his own political interests above all other considerations, starting with his party’s. If it helps him to push for work permits in 2013 and then claim now that that was just a poison pill, that’s what he’ll do. The more Rubio can weaken perceptions of Cruz as a conservative bulwark, the less of an argument Cruz has that he should be the nominee instead of Rubio if they square off later.

But as I say, this is only half true. The reason Cruz’s colleagues dislike him isn’t just that he’s conspicuously self-interested, it’s that his self-interest depends on pandering to conservatives. Does anyone think Orrin Hatch or Trent Lott or any of the other Beltway heroes who’ve knocked Cruz this week would hold it against him if he were “incredibly calculated” in pandering to special interests favored by the Republican leadership, like the Chamber of Commerce? Go re-read the quotes from lobbyists in yesterday’s WaPo story about Republican movers and shakers flirting with Trump. They admit openly that they oppose Cruz because he’ll make it harder for them to do business. In fact, I can think of someone who’s done some pretty impressive calculating himself in pandering to Team Hatch/Lott. Rubio ran for the Senate criticizing an “earned path to citizenship” as amnesty in 2010. When he got elected, he turned around and supported an immigration bill that included — ta da — an earned path to citizenship. Then he went on conservative talk radio to try to sell it to the right, wisely realizing that he’d preserve more goodwill in the aftermath by engaging conservatives than by ignoring them. And then, when the immigration thing blew up on him anyway, he began moving right by insisting that Obama had ruined any chance of comprehensive reform and that a “security first” bill of the sort preferred by many border hawks was the only option. Pretty calculating, and every turn was designed to maximize Rubio’s self-interest — he was anti-amnesty in 2010 in riding the tea-party wave to victory, then pro-amnesty in 2013 after the party started panicking about Romney’s electoral showing with Latinos (which was useful in introducing him to wealthy donors before this year’s presidential run), now he’s somewhere in between because he’s trying to be the guy who can unite the center and the right. Are Cruz’s calculations worse because he’s more obvious about it, or because he’s better at it? Or because they’re aimed at the wrong constituency?

Ben Domenech offers another reason why GOP senators look especially dimly on Cruz’s form of calculation. It’s not just that he’s pandered to the right by opposing the leadership. It’s that he’s been more politically successful with that strategy than anyone expected, which means there are bound to be copycats to come among ambitious young pols:

Yes, Cruz himself is an existential threat to the established order in Washington, someone with the potential to reorient a party coalition and blow up the existing gravy train. But everyone in Washington who depends on that order is convinced that he’s a general election loser. So why the palatable underlying fear for the disruption a Cruz nomination could bring? If they’re so certain he’s going to lose, why worry?

Because the threat smart members of the Washington political elite truly believe in is not Ted Cruz, but the model he represents: that the path for an ambitious freshman politician to achieve leadership of the Republican Party in this day and age is not the normal give and take and deference to leaders and precedent and the way we do things around here, but instead to take a flamethrower to this system from day one. Regardless of whether Cruz wins a general election, his nomination could fundamentally transform the political incentives of the Senate and change the internal dynamics of the Senate Republican Conference. It shows that you can get a shot at the presidency not by playing along, but by playing your own game.

Rubio’s dancing around that here in criticizing Cruz for “calculation,” just as he’ll dance around it when he eventually starts attacking Cruz for being “divisive.” But he can’t say what Domenech said explicitly or else it’ll be taken as criticizing Cruz for having obstructed Republican leaders, which is the same “establishment” argument Trump’s been making lately. Trump can afford to annoy Cruz fans by seeming to ally with Mitch McConnell; Rubio, who wants to be their second choice, can’t. So he’s going to go on arguing, in oblique terms, that Cruz doesn’t really believe any of this conservative populism he’s been selling and that this is essentially just a long con at the right’s expense designed to give him a foothold in the presidential primaries. This is a taste of that theory.