CRAWFORD, Texas &

The door is closing on President Bush's opportunity to shape domestic policy.

His strength is sapped by an unpopular war, Democrats are running Congress, and the 2008 presidential election is in full roar, distracting attention from the president's priorities. With dwindling options, Bush has decided he might get more done in his final months by going it alone.

Outgoing presidents often unleash a flurry of executive orders and regulations in a last-minute attempt to leave their mark on U.S. policy. Frustrated by Congress' inability or unwillingness to pass the president's agenda, the administration already is taking steps to do it through executive action.

With his immigration bill dead, the administration rolled out a proposed rule to address some of the major issues in the failed legislation. It will tighten border security, streamline guest-worker programs and pressure employers to fire illegal immigrant workers.

Bush said it was an example of acting within the boundaries of existing law when Congress failed to act.

Energy is another area where Bush is ready to go solo.

In his State of the Union address in January, Bush urged Congress to expand the use of alternative fuels to cut U.S. dependence on foreign oil. The president's energy proposal &

dubbed 20 in 10 &

aims to cut gasoline use by 20 percent in 10 years.

With the House and Senate struggling to compromise on their own energy measures, the president asked the head of the Environmental Protection Agency and Cabinet secretaries to see how much of his energy proposal could be accomplished through regulation &

without congressional action.

"The president hopes Congress will return to Washington in September ready to work," said Joel Kaplan, Bush's deputy chief of staff for policy. "Now with that said, of course we're considering things that the president can do through his executive and administrative authorities. But, again, there's a long way to go in the legislative calendar."

Congress is on its August break, and the president is spending a working vacation at his Texas ranch.

With 17 months left in office, Bush has veto power and an arsenal of other executive powers to change policy. But his critics say he moved across a symbolic line toward lame duck status on Monday when his longtime political adviser, Karl Rove, announced he was leaving &

the latest in a growing line of senior officials to head for the door in the closing months of the administration.

Rove said there was unfinished business on energy, education and health care that the president would continue to pursue &

with or without Congress' help. Rove said the administration might end up doing things by executive action.

"We have No Child Left Behind, which we can either do by law or regulation; we want to do it by law," Rove said. "The energy, 20-in-10 we can do both by legislation and regulation."

The Democratic Congress is going to be challenging Bush every step of the way &

on his agenda, the budget and particularly the war in Iraq &

as he runs out of time and influence and 2008 elections overshadow him.

John Podesta, former White House chief of staff for President Clinton, said Bush is "running into a brick wall in Congress" and will be forced to use executive action to further his domestic policy desires.

"Hardly a bill goes by that he doesn't issue a veto threat," Podesta said. "The places where he could find common ground, he's in a 'just say no mode.' I find that kind of surprising given the place he's at in his presidency."

White House advisers blame the Democratic Congress for some inaction on the president's agenda, although it was Bush's fellow Republicans who helped sink his immigration bill.