Senate Republicans Monday blocked Mari Carmen Aponte, President Barack Obama's choice to be ambassador to El Salvador, stating there were unresolved questions about whether Cuban intelligence officials tried to recruit her as a spy in the 1990s.

Democrats said the FBI cleared Aponte of any wrongdoing. She is currently serving as ambassador after receiving a recess appointment last year. But that appointment expires at the end of the year unless the Senate acts to confirm her nomination.

The Aponte vote was the third time in a week that Senate Republicans have used a procedural tactic known as a filibuster to block a presidential appointment. The Senate voted 49 to 37 for Aponte, short of the 60 votes needed to cut off debate.

Sen. Jim DeMint, R-S.C., one of the Senate's most conservative members, led the effort to defeat Aponte. Primarily, the questions centered around the 12-year romantic relationship she had with a man who was targeted as part of an FBI counterintelligence investigation and allegedly worked for Cuba's spy agency, DeMint said on the Senate floor. DeMint also complained about a June op-ed Aponte wrote in a Salvadoran newspaper concerning gay rights.

DeMint noted that the Aponte article riled conservatives in El Salvador who formed a coalition urging the Senate to reject her nomination. The coalition, which includes dozens of organizations from El Salvador and other countries like Mexico and Honduras, said the only thing that they agreed with Ms. Aponte about is that violence against homosexuals should be repudiated, DeMint noted.

Sen. Dick Durbin, D-Ill., spoke in support of Aponte. The article was entitled, 'For the Elimination of Prejudices Wherever they Exist.' Her op-ed disavowed violence and hatred against individuals based on their sexual orientation, urging education and understanding, Durbin said.

Those are hardly radical ideas. Most members of the Senate, at least let's say many members of the Senate, have given speeches along these lines, he added.

The vote on the Aponte nomination came after the Senate voted 70 to 16 to cut off debate on the nomination of Norman Eisen to be the ambassador to the Czech Republic. The nomination was then confirmed by voice vote.