WASHINGTON — The different paths Senators McCain and Obama have taken to support expanded offshore drilling for oil demonstrate how each would govern as president, their supporters said yesterday.

Mr. McCain’s surrogates contended on yesterday news programs that the Arizona Republican’s turn toward drilling, which he had once opposed, showed how Mr. McCain would respond decisively to a crisis. Mr. Obama’s supporters argued that his willingness to consider a bipartisan proposal including more drilling showed how the Illinois Democrat would pursue compromise to achieve results.

Senator Lieberman, a Connecticut independent who is backing Mr. McCain, was skeptical of Mr. Obama’s support of 10 senators, half of them Republicans and half Democrats, promoting compromise legislation including drilling and other energy-related initiatives.

“John McCain sees the crisis,” Mr. Lieberman said, who also once opposed more offshore drilling.

“Barack Obama says this weekend, ‘maybe,’ ‘eh,’ ‘and,’ ‘if,’ ‘but.’ He did not endorse, he did not come out with a strong decision,” Mr. Lieberman said on “Meet the Press” on NBC. “I predict to you he’ll find reasons not to be for it if this comes to a vote in the Senate.”

Senator Kerry, a Massachusetts Democrat, appearing with Mr. Lieberman, said Mr. Obama remains opposed to drilling but is prepared to “break America’s gridlock by honoring a bipartisan effort, if that is the only way to move us towards alternative and renewable fuels and an energy policy that’s comprehensive.”

Both Messrs. Obama and McCain opposed expanding oil exploration on American coastlines when they were seeking their parties’ nominations for president. As oil prices shot upward and gasoline edged toward $4 a gallon, Mr. McCain — with the Republican nomination sewn up — announced that he would support drilling because of spiraling energy costs.

Mr. Obama said last week that he remained opposed to additional offshore drilling but would consider it as part of a plan promoting fuel-efficient cars and developing alternate energy sources.

McCain has long touted his reputation as a Republican maverick who crosses party lines to seek compromise even if it annoys fellow party members. Senator Graham, a Republican from South Carolina, contrasted Mr. McCain’s change of heart on drilling with Obama’s on public financing for his presidential campaign, which Obama at first favored and then rejected.

Mr. Obama’s supporters repeated their argument that new offshore oil exploration would take nearly a decade to produce any oil, thus not affecting gasoline prices yesterday. They also said oil companies should first start drilling in the millions of acres for which they already hold leases.