But increasingly in recent months, the administration has been seeking ways to act without Congress. Branding its unilateral efforts "We Can't Wait," a slogan that aides said Mr. Obama coined at that strategy meeting, the White House has rolled out dozens of new policies - on creating jobs for veterans, preventing drug shortages, raising fuel economy standards, curbing domestic violence and more.

Each time, Mr. Obama has emphasized the fact that he is bypassing lawmakers. When he announced a cut in refinancing fees for federally insured mortgages last month, for example, he said: "If Congress refuses to act, I've said that I'll continue to do everything in my power to act without them."

Aides say many more such moves are coming. Not just a short-term shift in governing style and a re-election strategy, Mr. Obama's increasingly assertive use of executive action could foreshadow pitched battles over the separation of powers in his second term, should he win and Republicans consolidate their power in Congress.

Many conservatives have denounced Mr. Obama's new approach. But William G. Howell, a University of Chicago political science professor and author of "Power Without Persuasion: The Politics of Direct Presidential Action," said Mr. Obama's use of executive power to advance domestic policies that could not pass Congress was not new historically. Still, he said, because of Mr. Obama's past as a critic of executive unilateralism, his transformation is remarkable.

"What is surprising is that he is coming around to responding to the incentives that are built into the institution of the presidency," Mr. Howell said. "Even someone who has studied the Constitution and holds it in high regard - he, too, is going to exercise these unilateral powers because his long-term legacy and his standing in the polls crucially depend upon action."