Aiken, S.C. — Two-and-a-half days out from the primary here, South Carolina governor Nikki Haley has thrown her support behind Marco Rubio.

Right now, Haley boasts a whopping 81 percent approval rating in the state, so her last-minute endorsement is a real coup for Rubio. Campaign sources tell me their polling shows him battling Ted Cruz for second place right now, so Haley’s endorsement could make a different in a tight race, and I suspect that’s why she made it. Haley delivered the GOP response to the State of the Union last month and she is often mentioned as a potential vice-presidential nominee.

Haley, Senator Tim Scott, and Rubio’s Super PAC share a pollster, the low-profile GOP strategist Jon Lerner. Conspiracy theorists, go nuts.

I’m here at a Rubio town hall, where an overflow crowd is milling in the lobby and outside a rec center. Scott, who has also endorsed Rubio, is roaming around and chatting with people, and taking pictures with a lot of kids.

It’s interesting: Donald Trump and Ted Cruz seem mired in a vicious back-and-forth right now. Cruz held the first press conference of his campaign earlier today to invite Trump to sue him over an attack ad Trump found objectionable. Trump has been hammering Cruz in dozens of interviews as the biggest liar he’s ever come across. And the Cruz campaign got too clever by half with Ben Carson in Iowa, and neither Trump nor Rubio have been willing to let that drop from the public discourse. Together, it’s created a climate of real nastiness between the two frontrunners, and Rubio looks to be coming up the middle.

His message remains essentially positive. It took his campaign a few days to figure out how to respond to a disastrous debate in New Hampshire, but he’s off his usual stump speech. His remarks here in South Carolina are focused on poverty and veterans, and he’s promising to unite and expand the reach of the party.

“All those people who hate me? Well, I’m gonna cut their taxes too,” he said.