WASHINGTON, Oct. 27 - George W. Bush has been in the White House for 248 weeks, through a terrorist attack, two wars and a bruising re-election. But it seems safe to say that he has never had a worse political week than this one -- and it is not over yet.

"I think all bets are off," said former Senator Warren B. Rudman, Republican of New Hampshire. "Who knows what's next?"

The biggest question for Mr. Bush now is what he can make of the 39 months remaining in his presidency. For this horrible week has been months -- even years -- in the making. The 2,000th American fatality in Iraq was just the latest daunting milestone in a war that will soon be three years old. The C.I.A. leak investigation that threatens to indict a top White House aide or two on Friday grew out of the fierce debates over the flawed intelligence that led to that war.

And Harriet E. Miers's withdrawal of her nomination to the Supreme Court is the bitter fruit of Mr. Bush's own frailty in the wake of all those storms -- and Hurricane Katrina -- and of his miscalculations about how her appointment would be received.