President Barack Obama’s pick to lead the Transportation Security Administration withdrew his nomination Wednesday under fire from Senate Republicans, accusing his opponents of scuttling his bid for political gain.“It is clear that my nomination has become a lightning rod for those who have chosen to push a political agenda at the risk of the safety and security of the American people,— Erroll Southers said in a statement. “This partisan climate is unacceptable and I refuse to allow myself to remain part of their dialogue. The TSA has important work to be done and I regret I will not be part of their success.—But Sen. Jim DeMint (R-S.C.), who led the charge to hold up the nomination, issued a statement suggesting Southers’ integrity was in question and accusing the White House of failing to cooperate with Republicans who questioned his nomination. “Americans deserve a leader at TSA with integrity and with an unwavering commitment to putting security ahead of politics,— DeMint said. “The White House never responded to requests for more information relating to Mr. Southers’ false testimony to Congress and his censure by the FBI for improperly accessing files. And Mr. Southers was never forthcoming about his intentions to give union bosses veto power over security decisions at our airports. TSA screeners can already join unions, but collective bargaining would force TSA officials to ask union bosses for permission to make critical security changes.—A White House spokesman said Obama regretted Southers’ decision to withdraw and that he would have made an “excellent TSA administrator.—