First Trey Gowdy, then Tim Scott, now Nikki Haley: That’s not a bad crop of endorsements to have in South Carolina.

This could be just the nudge Rubio needs to finish a very distant second to Trump.

U.S. Sen. Marco Rubio will win South Carolina’s most Republican coveted endorsement of the 2016 presidential race when Gov. Nikki Haley announces her support at a Chapin rally on Wednesday evening, a source with knowledge of the governor’s decision told The State.

Haley, the state’s most popular GOP politician in polls, has decided to back the establishment candidate considered to be in best position to challenge Republican front-runners Donald Trump and Ted Cruz…

Haley’s decision was a bit of a reversal in the past day. The governor told reporters Tuesday that she had not made up her mind on who to back in the 2016 race…

They have communicated while Rubio has been on the trail. The senator also has said during stops in South Carolina this week how Haley would make a good vice president.

Haley always seemed like a natural match for Rubio — until last month. Indulge me as I quote myself in a post from mid-January:

Haley’s political persona has always seemed to me much more like Rubio’s than Ted Cruz’s — sunny, disinclined to bomb-throw, self-conscious about being a “next generation Republican,” willing to make common cause with the left even on fraught policy matters (immigration, the Confederate flag debate). The playbook, I thought, was for Rubio to perform well in New Hampshire, earn a bunch of influential vote-of-confidence endorsements from prominent Republicans in South Carolina (starting with Haley), surprise everyone with a strong showing there, and then battle Cruz and Trump on an even footing in the SEC primary and Florida. You can remove Haley from the playbook now.

That was written on the day she went out of her way in a press conference to say that, unlike Marco Rubio, she doesn’t believe in “amnesty.” There was no way she’d shank him like that, I thought, if she hadn’t already ruled out endorsing him before South Carolina. In fact, there was known to be bad blood between Team Haley and some of Rubio’s people dating back to their time as local operatives in SC, which might have explained the “amnesty” attack. At the very least, Haley seemed to be signaling last month that her endorsement was still in play.

And you know what? Maybe it was. Team Cruz supposedly made a “feverish bid” for her support, pitching her on the idea that her criticism of Trump in her SOTU rebuttal had damaged her populist cred and backing Cruz would be one way to restore it. Team Jeb had been courting her for ages, believing that Haley’s backing would have been a shot of credibility for his candidacy that Bush could take to his wavering donors as proof that even the party’s young stars still believe he’s in this thing. (George W. Bush made a point of complimenting Haley in his speech at Jeb’s rally this week.) I wonder what would have happened if either of them had showed some strength in recent polls of SC. If Cruz and Trump were neck and neck with Rubio a distant third, Haley might have concluded that Rubio was on his way out of the race and it was Cruz or bust. If, on the other hand, Jeb was neck and neck with Rubio for third, that might have been enough for Haley to roll the dice on him as the center-right’s best chance. As it is, despite his setback in New Hampshire, Rubio’s done well enough lately to make him the safest pick for Haley. His favorable rating hasn’t tanked like Cruz’s has, giving Rubio a decent shot at a surprise second in SC, while Jeb’s been in single digits in multiple polls this week, leaving him poised to flame out of the race on Saturday night. I think that’s the real value of this endorsement to Rubio — not that it’s going to put a dent in Trump’s lead (Haley backed Romney in 2012 and Newt Gingrich still won the state easily) but that it’s a signal to voters that Cruz and especially Bush are playing losing hands. Rubio denied his opponents some electoral oxygen by landing her.

I don’t think it’s a coincidence either that Rubio’s been talking her up as a potential VP. She’s always seemed the most likely person to end up on a ticket with him, I’ve thought, given the similarities I described in the excerpt above. If Rubio finds a way to get past Trump (er, how?), he’d run against Hillary as the leader of a new, young, more diverse GOP and he’d want a running mate who fits that bill but also has executive experience and ideally is female to hedge against Clinton’s “first woman president” pitch. Is there anyone you know who matches that description? Here’s Haley from last month distancing herself from her future running mate and “amnesty.”

Update: Yep, this should be coming soon now:

Ok Mitt, the water is warm. Get it out there in time for NV…

— Liam Donovan (@LPDonovan) February 17, 2016

Romney held off before New Hampshire because Christie and Bush were still in the thick of it with Rubio. Christie’s gone now and Bush is fading, and Nevada famously has a large Mormon minority. Rubio will want Romney’s endorsement badly before the caucus there and Romney really has no reason not to give it now. That should happen sometime soon — possibly before South Carolina votes on Saturday.