Karl Rove said the first thing he planned to do after leaving the White House was go duck hunting in Texas. It was an unfortunate choice of getaway considering that his resignation this week added to the impression of George W. Bush as a lame duck president.

The departure of Mr Bush’s chief political strategist was viewed in some quarters as a symbolic moment marking the end of the administration as a force in domestic policymaking.

Power has been draining from Mr Bush all year as the Democratic Congress has blocked his agenda, while chaos in Iraq continues to sap his credibility. The early start to the 2008 presidential election campaign has further eroded his influence as attention shifts to the candidates vying to replace him.

Asked by Fox News this week how much time was left for Mr Bush to advance his agenda, Charles Krauthammer, the conservative commentator, said: “None. It’s over… There is no agenda.”

Mr Bush began his second term with an ambitious legislative programme, including reform of the social security system, but one by one his proposals have stalled on Capitol Hill. The collapse of a bipartisan immigration bill in June ended his last realistic hope of a second term domestic legacy.

White House officials insist there is still much that can be achieved during his remaining 17 months in office. “While the window on major legislation might be closing, there is certainly enough time to get some things done,” said Dana Perino, deputy press secretary.

Among the objectives: reauthorisation of the No Child Left Behind education law; ratification of trade agreements with South Korea, Columbia and Peru; and energy efficiency measures designed to cut US gasoline consumption by 20 per cent. But even this relatively modest agenda faces multiple obstacles on Capitol Hill.

Grover Norquist, a conservative activist and president of Americans for Tax Reform, says the remainder of Mr Bush’s term will be defined not by what he achieves but instead by his ability to veto Democratic legislation. “If the question is what laws can the Bush administration pass before January 2009, the answer is: zero. But what they can do is stop the Democrats passing bad laws,” he says.

Mr Bush has already vetoed efforts to bring troops home from Iraq and he has threatened to wield his veto again next month against a series of Democratic spending bills that exceed the White House budget request.

Robert Greenstein, executive director of the Centre on Budget and Policy Priorities, says Mr Bush wants a fight over spending to burnish his tax-cutting credentials and restore the Republicans’ reputation for fiscal responsibility.

Use of the veto is Mr Bush’s strongest remaining source of domestic authority because it forces Congress to negotiate with the White House. “He is attempting to make sure he remains a player,” says Mr Greenstein.

Second term US presidents have traditionally focused on foreign policy when their domestic power fades. Mr Bush has launched a push to revive the Middle East peace process and become more engaged in efforts to tackle climate change. But ill-feeling caused by the war in Iraq limits Mr Bush’s ability to play the statesman role adopted by Ronald Reagan and Bill Clinton.

Foreign policy and military strategy are among the few areas where a US president has sweeping powers to act independently of Congress. But he is unlikely to relish the two biggest decisions he faces before leaving office. Should the US withdraw from Iraq? And what should be done about Iran’s nuclear programme? A lame duck at home, some of Mr Bush’s actions could yet carry weighty consequences.