Dave Weigel points out the limits of “Tea Party” resistance to Romney’s nomination:

The takeover in 2010 wasn’t as complete as they thought. Marco Rubio’s a good case study. He defined himself, and let the media define him, as the “Tea Party” challenger to Charlie Crist. This was easy; from the anti-stimulus, anti-Obama perspective, Crist was an abysmal candidate. But there was no deep reasoning behind this. Rubio was an establishment Florida Republican who was very smart about branding [bold mine-DL]. In power, he did nothing to stop the rise of Mitt Romney; eventually he endorsed him. Jim DeMint did nothing to stop Romney, whom he’d endorsed in 2007.

This is a useful reminder that Rubio was the long-shot challenger against a better-known opponent for the Senate nomination, but he was not an insurgent-type candidate by instinct or on policy. Not only did he do nothing to stop Romney, but at an important moment before the Florida primary he helped cut the legs out from under the already-collapsing Gingrich. He rebuked Gingrich’s “anti-immigrant” line for his own reasons, and his enthusiasm for Romney has never been great, but that small intervention helped Romney just enough at a moment when he needed it. Besides, why would Rubio want to stop Romney? Based on past records, Romney may be less of a credible conservative than Crist, but he is a more credible opponent of Obama than Crist was. Rubio and Romney are both strong partisans at this point, and it is partisan antipathy to Obama that matters more in this cycle than having a reliably conservative record.