The probe into how two uninvited Washington socialites managed to masquerade onto White House grounds during the Nov. 24 state dinner moves to Capitol Hill today, where the House Homeland Security committee will try to get some answers.
Witnesses called to testify on "gate-crash-gate" include the director of the U.S. Secret Service, Mark Sullivan, White House social secretary Desiree Rogers and the alleged crashers, Tareq and Michaele Salahi.
But at least three of the witnesses for the hearing -- which is billed as "an examination of a system failure" -- have indicated they won't show.
The Salahis' attorney, Paul Gardner, said his clients won't be there, and the White House, claiming executive privilege, has shielded Rogers from Congress' questions.
"I think, you know, that, based on separation of powers, staff here don't go to testify in front of Congress. She won't. ... She will not be testifying in front of Congress," White House press secretary Robert Gibbs told reporters Wednesday.
That decision drew criticism from some Republicans on the committee, who suggested the White House is acting as if it has something to hide.
"I just think they're afraid to take the heat," said Rep. Peter King, R-N.Y. "They're hiding behind the separation of powers argument, which is not a real argument, and they're stonewalling."
Senior White House adviser Valerie Jarrett refuted those claims on "Good Morning America" today, saying the White House prides itself on transparency and has made the results of its internal review public.
"I think having a full review up on the Web site where anyone can read it is the definition of transparency," said Jarrett. "We think it's important to have a balance and have the White House staff have confidential conversations with the president and his team and not go testify before Congress.
"We think we've really answered the questions fully," she said.
One question still unanswered is why Rogers decided not to have a staff member standing at the entrance to assist the Secret Service in checking guest lists at the state dinner, as has been common practice in previous administrations.
On Nov. 24, Rogers attended the state dinner as a guest and told reporters which designer she was wearing.
In a memo issued this week, White House Deputy Chief of Staff Jim Messina instructed Rogers' office to abide by precedent and have a White House staffer present at checkpoints during official events.
"After reviewing our actions, it is clear that the White House did not do everything we could have done to assist the United States Secret Service in ensuring that only invited guests enter the complex," Messina wrote.
Still, the Secret Service has assumed full responsibility for the breach, saying in a statement last week that it is "embarrassed" and "deeply concerned." Its review is ongoing.
"Whatever created this breach, we want it fixed," said House Homeland Security committee Chairman Rep. Bennie Thompson, D-Miss. "Then we can get on with securing the president and his guests, and Secret Service can continue to do what they've done so well in the past."
Thompson has said the committee may legally require the Salahis to testify if they fail to show at today's hearing.
"If the Salahis are absent from tomorrow's hearing, the committee is prepared to move forward with subpoenas to compel their appearance," he said late Wednesday.