President Barack Obama will not allow White House Social Secretary Desiree Rogers to testify before Congress on Thursday about her role in the security breakdown that allowed a pair of uninvited guests to crash the White House state dinner last week.“I think you know that based on separation of powers, staff here don’t go to testify in front of Congress,— White House Press Secretary Robert Gibbs said Wednesday. “She will not be testifying in front of Congress tomorrow.—Rogers had been invited to testify before the House Homeland Security Committee. Rogers has acknowledged that no one from her office was at the checkpoint for the state dinner to help identify guests.Gibbs said Obama thinks Rogers is doing a great job. “The president, the first lady and the entire White House staff are grateful for the job that she does and thinks she has done a terrific and wonderful job pulling off a lot of big and important jobs here at the White House,— Gibbs said.