Getting confirmed to the federal bench is not easy – and given the fact that confirmation means the judge has a lifetime appointment, it is understandable that Senators are cautious about who they support.

At the federal district court level, Senatorial courtesy is pivotal to the process. As a result, it is pretty rare that a home-state Senator will withdraw support for a nominee once they have endorsed that candidate.

Months ago, Senator Marco Rubio and Senator Bill Nelson agreed to the nomination of William Thomas. William Thomas is a Circuit Judge for Florida’s Eleventh Judicial Circuit. He has a good reputation as a trial judge (although for reasons that are not clear, he is not a member of the American Judges Association which would, of course, welcome his membership).

Recently, however, Jennifer Bendery reported in The Huffington Post that Senator Marco Rubio has withdrawn his support for federal judicial nominee Judge Thomas, and is now blocking his nomination.

Senator Rubio originally recommended Thomas to President Obama in late 2012 to fill a vacancy in the U.S. District Court for the Southern District of Florida. The vacancy has been declared a “judicial emergency” by the Administrative Office of the U.S. Courts. The judgeship Thomas has been nominated for has been open for more than 18 months.

If confirmed, Judge Thomas would be the first openly gay black man to serve as a federal judge. A spokeswoman for Senator Rubio told The Huffington Post that, “the senator decided to pull his support after ‘a thorough review’ of Thomas’ record, including two cases that Thomas handled as a Miami-Dade circuit judge.”

The spokeswoman had no explanation as to why the Senator did not know of these cases before the nomination and his endorsement of Thomas, nor why it took months for him to find the cases.