Today, Marco Rubio announced that he will oppose Thomas Perez to fill President Obama's Secretary of Labor post, just hours before the nomination was set to go before a Senate committee. The post has been vacant since Hilda Solis left in January.

In a press release, Rubio said, "Our nation deserves a proven administrator who is committed to maximizing opportunities for the American worker, not a liberal activist who has pushed the boundaries of public office to advance his agenda."

Perez, 51, was Maryland's labor secretary from 2007 to 2009, before serving as Assistant U.S. Attorney General. Because Democrats control the Senate Health, Education, Labor and Pensions Committee, he is expected to clear that vote. But when he comes up for a vote before the entire Senate, well, it may be too soon to predict the outcome.