When former President Bill Clinton, Costa Rica President Oscar Arias and top officials from across the hemisphere attend the Americas Conference in Coral Gables, Fla., today, one of the issues that will surely come up is whether anybody is in charge of U.S. policy toward Latin America.

The Obama administration’s nominee for top State Department official in charge of hemispheric affairs, Arturo Valenzuela, has not yet been confirmed by the Senate. As a result, Latin America is the only State Department geographic regional office without an Obama administration appointee.

Another key Obama regional nomination, that of current State Department hemispheric affairs chief Thomas Shannon as U.S. ambassador to Brazil, has also been delayed in the Senate.

Conservative Sen. Jim DeMint, R-S.C., has blocked both Valenzuela’s and Shannon’s confirmations to protest the administration’s handling of the Honduras crisis.

“It’s a problem,” says Jeffrey Davidow, a former State Department official in charge of hemispheric affairs who now presides over the La Jolla-based Institute of the Americas. “We are left without a new assistant secretary who was chosen to implement the policies of the new administration, and without an ambassador to arguably the most important country in the region.”

Davidow, who is very close to the Obama administration, told me that “DeMint’s action is totally counterproductive” in the midst of the Honduras crisis. Washington needs a visible voice representing the Obama administration in ongoing diplomatic talks, and an ambassador to Brazil, a key player in the crisis since ousted Honduran President Manuel Zelaya took refuge at the Brazilian Embassy in Honduras.

“This is a time that calls for increased levels of communication,” Davidow said.

Late last week, I called Sen. DeMint and asked him for how long he plans to continue holding up these nominations.

“I will not lift the hold on these nominations until the United States works out an arrangement with the Honduran government to recognize the outcome of the (planned Nov. 29) elections in Honduras and restores the U.S. foreign aid that has been cut by the Obama administration,” DeMint said.

“They (the Obama administration) continue to use the misguided rhetoric that what happened in Honduras was a military coup, when it’s obvious by the facts and the documentation that the Honduran government acted according to its own constitution,” DeMint added.

Hmm. And what does he say about Democrats’ charges that he is irresponsibly hampering U.S. policy in the region?

“They are showing very little respect for the American Constitution and very little respect for the constitution of Honduras,” DeMint said. “The United States is siding with (Raul) Castro, (Daniel) Ortega and (Hugo) Chavez in this situation.”

U.S. officials reject speculation that nobody is in charge of U.S. policy toward the region. Shannon, a well-respected diplomat who has been doing the job for nearly four years, continues running the office, they say.

Other diplomatic sources say that while Shannon is still in charge, he has been lying low in recent months, avoiding public appearances that could further complicate his Senate confirmation.

My opinion: This is Washington partisan politics at its worst. I doubt that DeMint, who is not known to have ever cared much about Latin American affairs, would have blocked Obama nominations for top State Department jobs in charge of other parts of the world that most in Washington consider more important.

Granted, Democrats have blocked Republican nominees for Latin American affairs in the past, using similar petty excuses to settle domestic scores. If DeMint is so unhappy about Obama’s Honduras policy, he should do what senators do: try to muster enough votes in Congress to change U.S. policy.

But blocking Valenzuela and Shannon’s nominations is depriving the State Department of the manpower and political weight it needs to confront ongoing crises in the region. It’s irresponsible, cowardly and — not the least — dumb.