Of course George Bush is a lame duck. His poll numbers are dreadful, a hostile Democratic leadership runs Congress and core advisers like Karl Rove are checking out.

But any president – even one this diminished – retains enormous power to shape public policy. And every sign indicates that Bush plans to use that power “right up to the moment that he leaves,” as Rove told Fox News.

There are some things the president can no longer do. Appoint strict conservatives to the federal bench, for one. In fact, Bush’s ability to fill any post requiring Senate confirmation is limited. Attorney General Alberto Gonzales is still around partly because any replacement would face such tough grilling on Capitol Hill.

The president’s power to enact legislation has also drained away. Witness his failure to revise immigration laws. Many Republicans no longer feel afraid of, or loyal to, this White House and they are more interested in getting re-elected than burnishing the president’s legacy.

But counting out this president would be a huge mistake. In at least 10 ways, Bush can be a potent player during his last 18 months in office:

COMMANDER IN CHIEF: While a strong majority opposes his Iraq policy, the president’s war-making power remains largely unchallenged. Even contenders for the Democratic nomination acknowledge that changing his approach will not be easy. “This is going to take a while,” said Sen. Hillary Clinton (New York) during the last debate in Iowa. Added Sen. Barack Obama (Illinois): “George Bush drove the bus into the ditch, and there are only so many ways you can pull that bus out of the ditch.”

BULLY PULPIT: The president has to limit his public appearances to friendly territory, like military bases, but he still has the biggest megaphone around. Classic example: Democratic leaders were petrified of his ability to criticize their handling of national security issues, and as a result, in the days before the August recess, they passed a bill giving the president expanded powers to conduct surveillance of terrorist targets.

INHERENT POWERS: The White House insists that a doctrine called a “unitary executive” is embedded in the Constitution. This means that legislation “is just advisory,” in the words of conservative legal scholar Bruce Fein, and “the president can still do whatever he wants to do.” One example: at a recent meeting with wiretapping experts, reported by The New York Times, White House lawyers “signaled that, in their view, the president retains his constitutional authority to do whatever it takes to protect the country, regardless of any action Congress takes” to limit his power to eavesdrop on suspected terrorists.

PERSONAL STUBBORNNESS: Top Republicans have urged Bush to fire the attorney general, but Gonzales remains in office. Democratic leaders have threatened to cite White House aides, who refuse to respond to congressional subpoenas, for criminal contempt. But if U.S. attorneys, who work for the Bush Justice Department, won’t pursue a criminal case, the Democrats can’t enforce their demands.