Press Secretary on Trial in the Briefing Room

It is I. Lewis Libby Jr., Vice President Dick Cheney's chief of staff, who is under indictment in the C.I.A. leak case. And it is Karl Rove, President Bush's senior adviser, who remains under investigation. But it is Scott McClellan, the White House press secretary, whose credibility is already on trial amid the rough justice of the briefing room.

More than two years ago, Mr. McClellan did what press secretaries are paid to do: He vigorously defended the president's men - specifically, Mr. Libby, Mr. Rove and Elliott Abrams, a national security aide who was never implicated in the case - against speculation that they had a hand in the disclosure of the identity of a Central Intelligence Agency officer.

"They're good individuals, they're important members of our White House team, and that's why I spoke with them, so that I could come back to you and say that they were not involved," Mr. McClellan said at his televised briefing on Oct. 7, 2003, one of several instances in which he denied that Mr. Rove and Mr. Libby were responsible for the leak.

As events have unfolded and the grand jury has heard testimony that both Mr. Libby and Mr. Rove had conversations with journalists that touched on the identity of the C.I.A. officer, Valerie Wilson, Mr. McClellan's reputation has been left dangling in the glare of the television lights.