Schwarzenegger's endorsement in the Republican primary of the 2008 U.S. presidential election was highly sought; despite being good friends with candidates Rudy Giuliani and Senator John McCain, Schwarzenegger remained neutral throughout 2007 and early 2008. Giuliani dropped out of the presidential race on January 30, 2008, largely because of a poor showing in Florida, and endorsed McCain. Later that night, Schwarzenegger was in the audience at a Republican debate at the Ronald Reagan Presidential Library in California. The following day, he endorsed McCain, joking, "It's Rudy's fault!" (in reference to his friendships with both candidates and that he could not make up his mind). Schwarzenegger's endorsement was thought to be a boost for Senator McCain's campaign; both spoke about their concerns for the environment and economy.

Who did Schwarzenegger finally endorse in the 2008 Republican primary?