WASHINGTON — John McCain has taken a modest lead over Barack Obama entering the final seven weeks of their presidential contest, buoyed by decisive advantages among suburban and working-class whites and a huge edge in how people rate each candidate's experience, a poll showed Friday.

The Republican McCain has had some success parrying his Democratic opponent's efforts to tie him to the deeply unpopular President Bush, according to the AP-GfK Poll of likely voters. Half say they believe the Arizona senator would chart a different path from Bush, including a slight majority of independents, a pivotal group of voters.

The survey has plenty of positive signs for Obama as well. The Illinois senator is generally doing about as well with whites as Democrat John Kerry did in his losing but close 2004 race against Bush. Obama has an 18-percentage-point lead over McCain among voters who look more to a contender's values and views than experience, and a modest advantage in the number of supporters who say they will definitely vote for their candidate.

Even so, the survey — conducted after both parties staged their conventions and picked their vice presidential candidates — conforms with others that have shown the Republicans grabbing the momentum after a summer in which Obama had steadily maintained a slim lead.

"My heart sort of runs with McCain and my mind probably tends to run toward Obama," said David Scorup, 58, a county government official in Othello, Wash. "I think I resonate more with McCain."

Underscoring how tight the race remains, several swing groups who traditionally help decide presidential races remain about evenly divided between the two tickets. These include independents, married women and Catholics.

Seven in 10 said Alaska Gov. Sarah Palin made the right decision in becoming McCain's running mate, despite the demands of a family whose five children include a pregnant, unmarried teenage daughter and an infant with Down syndrome. Men were slightly likelier than women to back her choice, and even Obama supporters were split evenly over whether she did the right thing.

"She was able to cope when she was governor of Alaska, so she must have great coping strategies," said Nancy Skinner, 58, a retiree and McCain supporter from Scottsbluff, Neb. She said Palin's decision to give birth to their youngest child, knowing he had Down syndrome, "shows she has compassion and is not afraid to face heartache and hard decisions."

McCain leads Obama by 18 points among whites, but his advantage peaks with certain types of voters. He is ahead by 24 points among suburban whites and 26 points with whites who haven't finished college, and has similar advantages with white men and whites who are married.

He also leads by a comfortable 23 points among rural voters and by 13 points with voters age 65 and over.

Obama leads 61 percent to 35 percent among voters under age 30. He has about a 5-to-1 edge with minorities and a narrow 5-point lead with women, though he trails among white women 53 percent to 40 percent.

On the Web:

AP-GfK Poll: www.ap-gfkpoll.com