These days, the “Let’s Roll” White House can do little better than careening from one mishandled moment to the next. There’s a palpable feeling that disorganization and poor judgment might become the hallmarks of the second half of George W. Bush’s presidency. Under siege on so many fronts, and with polls showing the president on the verge of being an outright liability for Republican congressional candidates in next year’s midterm elections, the Bush team’s season of bungling could be just a dire signal of worse things to come.

You know this presidency is in trouble when a senator from his own party publicly decries “chaos” at the White House, when the vaunted House GOP not only can’t muster 218 votes for a budget, but won’t even try, and when Vice President Dick Cheney has to look over his shoulder in trepidation of a special prosecutor coming down on his top aide — or even Cheney himself.

It means Bush is losing his clout, that he’s no longer feared, that his intraparty critics no longer worry that White House reprisals against them will have any punch — that he has, in fact, spent all of that “political capital” he claimed to have won just 11 months and three weeks ago.

A mismanaged response to a historic hurricane, a steady stream of bad news from Iraq, a grand jury investigation of White House officials and a Supreme Court nomination that is foundering are the headlines now. But even if those headlines fade away (not likely very soon), you can’t help get the feeling that what we’re seeing now is what the Bush presidency is going to look like for the next three years. The fact is, there is suddenly a leadership vacuum in the White House and on Capitol Hill, and as we all learned in Politics 101, power abhors a vacuum. If Bush can’t fill it, someone else soon will.

After Sept. 11, the president helped give the nation a rallying cry that popped onto bumper stickers everywhere and became the motto of his presidency: “Let’s Roll!” Right after he won re-election three years later, Bush portrayed himself at the zenith of his power, boasting that he would spend his newly acquired political capital — he was, after all, the first winner to since 1988 to take an outright majority of the popular vote — to assert his vision as never before.

Then right after his second inauguration, he launched his bid to overhaul Social Security, which even the GOP faithful on Capitol Hill quickly abandoned. It’s been downhill for him ever since.

How diminished is the administration’s power to manage the Bush agenda? Just last week Senate Judiciary Chairman Arlen Specter, who had to grovel for his gavel less than a year ago in the face of a conservative uprising, felt compelled to seize control of the otherwise adrift Harriet Miers confirmation effort (and humiliate the White House in the process), ordering the nominee to redo her Senate questionnaire. “I think it’s been a chaotic process,” said the senator, master of understatement.

Then Missouri’s Roy Blunt, who’s filling in as House majority leader for the indicted Tom DeLay, was unable to count on White House help and eventually had to punt a showdown vote on the GOP’s ambitious budget-cutting effort. That might not have been such a telling moment but for the fact that DeLay, when he was in charge, had made his reputation as a floor manager with no fear. We’ll get the votes on the floor, he’d always say, and then go on to break however many arms he needed to do so.

It did not help that so many in the White House were hunkered down with criminal defense lawyers as they were trying to strategize a winning scenario for an embattled court nominee.

If the climax of his inquiry is indictments, special prosecutor Patrick J. Fitzgerald’s investigation of a CIA agent’s outing could preoccupy this White House for months. Already it’s become a touchstone for the national debate on whether Bush used false pretenses to justify the Iraq War.

A former administration official fueled the debate last week, saying that Cheney and Defense Secretary Donald H. Rumsfeld have all but hijacked foreign policy in favor of military adventures. Lawrence Wilkerson, a deputy to Colin L. Powell when he was secretary of State, charged in a Washington policy speech that the arrogance of what he called the “Cheney-Rumsfeld cabal” had “courted disaster” in Iraq and elsewhere. Wilkerson even took a verbal shot at Bush, describing him as “not versed in international relations, and not too much interested in them, either.”

Second-term presidents have overcome tough times before. Ronald Reagan survived the Iran-Contra scandal to end on a high note. Bill Clinton beat impeachment. Their personal popularity was the key to survival. Bush’s personal appeal could save him, too. He is as low in opinion polls as Reagan or Clinton in their worst days. But if he doesn’t get his act together soon, his party could get rolled next year.

Contributing Editor Craig Crawford is a news analyst for MSNBC, CNBC and “The Early Show” on CBS. His new book is “Attack The Messenger: How Politicians Turn You Against The News Media.”