(MSNBC) — Florida Sen. Marco Rubio, a rising star in the Republican Party and a favorite among conservatives to round out the party’s ticket this fall, endorsed Mitt Romney for president on Wednesday evening.

Rubio’s endorsement is a marker of support that many candidates had sought. It comes at a point in the campaign at which Romney has sought to coalesce Republicans behind his candidacy.

Romney has spoken highly of Rubio in the past, describing him most recently as an example of “the American Dream” in an appearance Tuesday on Jay Leno’s “Tonight Show.”

Rubio has been a favorite among conservatives since his Senate bid in 2010, in which he managed to best moderate Florida Gov. Charlie Crist in the Republican primary, and eventually, in the general election (in which Crist ran as an independent).