WASHINGTON - Democratic senators rallied around President Obama's pick to head the Transportation Security Administration on Friday as new details emerged indicating that key lawmakers already knew when they voted in November to advance his nomination that he mischaracterized a personal incident in his testimony. The White House rushed to defend Erroll Southers, who is under fire for providing inconsistent statements to Congress about inappropriately accessing confidential criminal records 20 years ago about his then-estranged wife's new boyfriend. Democratic senators, meanwhile, intensified pressure to confirm Southers soon after Congress returns from its winter recess, saying it is critical that permanent leadership …