When was the last time Rubio had a poll this good? His top priority on Saturday night is finishing ahead of Cruz if possible, which would turbo-charge the media’s “Rubio comeback!” narrative. Failing that, he’ll happily accept third if Jeb Bush does so badly that his donors finally give up on him, clearing the way for Rubio to become the center-right choice in the race. According to PPP, Rubio’s got a shot at both: He’s tied with Cruz at 18 percent in a state that Cruz is supposed to do no worse than second in and Bush 2016 is on death watch at just seven percent here, tied with Ben Carson for fifth place. Trump’s going to win South Carolina, but the “electable” alternative may wake up on Sunday morning with his supporters newly energized and his “lane” suddenly clear ahead of Nevada.

The question is, if we did end up with a Trump/Rubio contest — and it’s hard to see how, given Cruz’s willingness and ability to run his race to the end — would the “electable” guy actually win? Trump’s numbers look awfully solid:

What’s striking about Trump’s support is how consistent it is across different demographic groups- he’s at 41% with ‘somewhat conservative’ voters, 40% with younger voters, 38% with men, 36% with self identified Republicans, 35% with Evangelicals, 35% with middle aged voters, 34% with non-Evangelicals, 31% with women, 30% with self identified independents, 30% with ‘very conservative’ voters, 30% with seniors, and 29% with moderates. He has a lead of some size within every single one of those groups, similar to what he was able to do in New Hampshire…

There’s been a lot of speculation that Trump might take on water after attacking George W. Bush on Saturday night, and Bush is relatively popular with 64% of voters seeing him favorably to 25% who have an unfavorable opinion. But despite his comments Trump is still leading even among voters with a positive view of GWB– he gets 26% to 22% for Cruz, 20% for Rubio, and 10% for Jeb Bush. And Trump is dominant with the swath of voters that doesn’t like George W. Bush, getting 57% to 12% for Kasich, and 11% each for Cruz and Rubio.

I’m going to take that as temporary vindication in the debate over whether Trump’s claim that Bush “lied” about WMDs Iraq is a problem or not. In a hypothetical three-way race in SC between Trump, Rubio, and Cruz, Trump ticks up to 40 percent while Rubio leaps to 28 percent, with Cruz a few points behind at 22 percent. In a hypothetical two-way race, Trump leads Cruz by 10, 48/38, but he leads Rubio by just one, 46/45. The reason is obvious: Center-right voters backing Bush and Kasich strongly prefer Rubio to Trump (and Cruz) and so they unite behind him when forced to choose. That’s good news for Rubio vis-a-vis Cruz but great news for Trump, who’s built enough support in the sort of evangelical-heavy state that’s supposed to look dimly at him that he could, in theory, now beat even Mr. Electable Marco Rubio head to head. It’s taken for granted among some anti-Trump conservatives that the only thing keeping Trump alive at this point is the deep divisions among the rest of the party between Rubio, Cruz, Bush, and Kasich, but what if that isn’t as true as it used to be? What if Trump is now sufficiently attractive even to Republicans outside of his hardcore base that a match race between him and Rubio, the candidate who’s capable of appealing to the right and to the center, would essentially be a dead heat? This is why there’s good reason to believe that it really will be too late to stop Trump once he has another couple of wins under his belt. If he gains credibility with each victory, then wins in SC and in the SEC primary on March 1 may leave even Rubio at a durable disadvantage that’ll be hard to reverse later.

The other big news from this poll, which is flying below the radar in write-ups about it, is Cruz’s favorable rating. Hoo boy:

That 42/48 split is the worst in the field, and the only numbers that are underwater among the six remaining Republicans. Cruz’s favorables were strong all through the second half of 2015, when, at one point, he was actually the most popular candidate in the field among Republicans. But that was ephemeral: Partly it was due to Cruz receiving high marks from Trump fans while their “bromance” was still in full bloom. Ever since Trump and Cruz went to war in January, Cruz’s favorables have been slipping and now PPP has them upside down. I think this is an outlier but there’s a chance that it isn’t given that (a) Trump is attacking Cruz relentlessly as a liar and a cheat in the media now and (b) Cruz has gone strongly negative against Trump and Rubio lately, which may be driving down perceptions of him. (It’s a weird irony that, among other candidates’ supporters, the only one that still rates Cruz favorably on balance is Ben Carson’s, whose campaign has been crying about Cruz’s “dirty trick” in Iowa two weeks ago.) Pay attention to other SC polls this week. If you see Cruz consistently pulling favorables that are lower than everyone else’s then he suddenly has a major, maybe insurmountable problem in trying to win a three-way race with Trump and Rubio — and maybe even a two-man race with Trump.

In lieu of an exit question, take a minute to scroll down to pages 12-15 of PPP’s crosstabs and note the difference between Trump’s (and, to a lesser extent, Cruz’s) voters and everyone else’s voters on a variety of cultural issues. I’ll leave you with these three as a sample: