WASHINGTON - The aftermath of the Christmas Day attempt to blow up a trans-Atlantic flight to Detroit would be all-consuming for the administrator of the Transportation Security Administration - if there were one.

The post remains vacant because Sen. Jim DeMint (R., S.C.) has held up President Obama's nominee in an effort to prevent TSA workers from joining a labor union.

DeMint, in a statement, said that the attempted airliner attack was "a perfect example of why the Obama administration should not unionize the TSA."

Two Senate committees have given Obama's nominee, Erroll Southers, a former FBI special agent and a counterterrorism expert, their bipartisan blessing.

DeMint, however, has objected to a full Senate vote, saying he wants additional testimony to clarify Southers' stand on unionizing the TSA - a shift that Democrats support. An acting administrator is in place at the TSA, the division of the Homeland Security Department that oversees airport security.

Senate Majority Leader Harry Reid (D., Nev.) hadn't scheduled a floor vote for Southers before the Senate left town Christmas Eve, and the Senate won't be back in session for three more weeks.

Reid spokesman Jim Manley said yesterday that the majority leader was working with the White House to get Southers confirmed "as quickly as possible," and he charged that "Republican obstructionism has prevented TSA from having the leadership in place that the organization deserves."

DeMint spokesman Wesley Denton said that Obama did not nominate Southers until September, and contended that Reid "has been too busy trading earmarks for votes on health care" to deal with the TSA nomination.

DeMint's objection creates a procedural hurdle that is likely to take at least three days of debate and test votes to overcome. Were that standard applied broadly to nominees, it could bring Senate business to a halt, said Manley, who called DeMint's opposition "disgraceful."

For now, DeMint said, the TSA has "flexibility to make real-time decisions that allowed it to quickly improve security measures in response to this attempted attack."

If organized labor were involved, DeMint said, union bosses would have the power "to veto or delay future security improvements at our airports."

He urged Obama to "rethink" supporting unionizing the TSA "and put the interests of American travelers ahead of organized labor."

Southers is the Los Angeles World Airports Police Department's assistant chief for homeland security and intelligence. He also is associate director of the University of Southern California's Center for Risk and Economic Analysis of Terrorism Events. He served as a deputy director of homeland security for California Gov. Arnold Schwarzenegger.