Three months ago, former Minnesota Gov. Tim Pawlenty (R) was arguably Mitt Romney’s most credible for the Republican presidential nomination, including the famous “Obamneycare” criticism. This morning, he’s a new, relatively high-profile ally.

Tim Pawlenty endorsed the presidential candidacy of Mitt Romney on Monday, making the announcement in an appearance on Fox News hours before the Republican presidential candidates gather in Florida for another debate. […]

Many of Mr. Pawlenty’s contributors and supporters had been waiting for a signal from him in the escalating contest between Mr. Romney and Mr. Perry. And Mr. Pawlenty had been looking for help to retire a campaign debt of at least $500,000.

Pawlenty will now serve as a national co-chair of the Romney campaign, and will reportedly travel with Romney to the debate in Florida this evening. One assumes Pawlenty will also now become a top campaign surrogate.

Of particular interest, Pawlenty took a shot at Rick Perry during his Fox News appearance, saying, “Gov. Romney wants to fix Social Security. He doesn’t want to abolish it or end it. Gov. Perry has said in the past that he thought it had ‘failed.’” Expect to hear quite a bit more of this line at tonight’s event.

Given Pawlenty’s poor showing in the race, his endorsement probably won’t change the landscape too much. It’s not as if the former Minnesota governor has a vast army of supporters and donors who will now flock to the Romney camp, helping the one-time frontrunner get back on top.

But there are a few interesting angles to keep in mind. For one thing, if Pawlenty still hopes to be on the ticket, this was probably a smart, early move. He denied any interest on Fox News this morning, but time will tell whether it was sincere.

For another, I wonder if this is the first big hint that the Republican Party establishment is starting to see Romney as the only viable alternative left in the GOP field. A week ago, Politico had a good piece on the Republican insiders/elites, who’ve largely remained on the sidelines, reluctant to get too invested at this point. Is Pawlenty’s move a sign of things to come? It’s something to keep an eye on.

Our ideas can save democracy... But we need your help! Donate Now!

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.