On May 7th, Marco Rubio was asked by Jason Mattera whether he would have voted for Arizona's new immigration law. He stated (humanevents.com/article.php?id=36858):

"The second one that passed hit the right note. Yes."

Now, he's changed his tune and on Spanish-language TV (link):

"The law, how it is now, do you support it, yes or no?" Maria Elvira Salazar asked on Mega TV's Maria Elvira Live.

"I don't support states taking this into their own hands," Rubio replied. "I think this needs to be dealt with at the federal level. What I support is the change they made to the law, because that improved the law."

Needless to say, that's not a good sign vis-a-vis Rubio's commitment to immigration enforcement.