Barack Obama pokes fun at his opponent, John McCain, on Friday during a rally in Abington, Pa.

WASHINGTON - Forget turning John McCain into a political punching bag. Barack Obama wants to turn his Republican rival into a punch line.

Obama is known for his soaring oratory, but lately he has been going for the laugh track - cracking frequent jokes.

He has taken to mocking McCain for stocking his campaign with ex-lobbyists while also promising to end their their influence in Washington.

"If you think those lobbyists are working day and night to elect my opponent just to put themselves out of business, well, I've got a bridge to sell you in Alaska," Obama riffs.

"It's the Leno-Letterman effect," said University of Virginia politics sage Larry Sabato. "The public is so conditioned to think about politics as the theater of the absurd, they like it when political information is delivered sounding like a comedy routine."

Obama still mixes in his message of hope and change, with dashes of passion, but along the way he regularly reels off lines that elicits chuckles.

Analysts say Obama wants to annoy and belittle his cantankerous opponent in the eyes of voters - without drawing a backlash. "A way of really getting under McCain's skin, and prompting the kind of intemperate reaction that might cost him voters, is to make fun of him," said Hunter College Prof. Ken Sherrill.

Talking Friday to a crowd in Abington, Pa., Obama didn't simply accuse McCain of being a recent, convenient convert to tighter Wall Street regulation. He got people to laugh about it.

"Suddenly a crisis comes and the polls change, and suddenly [McCain's] out there talking like Jesse Jackson. Come on," Obama scoffed as the crowd howled.

One reason for the smiling jabs is people like McCain. Calling him a hypocrite, liar or worse could anger folks.

"The tough stuff, the nasty stuff, that's what people are offended by hearing," said Sabato.

Experts point to Hillary Clinton as a prime example. She might have bested Obama in the primary, they say, if she cast herself more like Mae West than the Iron Lady. When she accused Obama of stealing lines, she denounced him furiously: "If your candidacy is going to be about words, they should be your own."

Obama took the alternate approach when McCain cast himself as the change candidate after the GOP convention.

"I notice John McCain has been trying to say 'I'm for change, too,'" Obama said recently. "He's been grabbin' our signs, using our slogans."

"He even said the other day, I think, 'turn the page.' C'mon John. I've been sayin' that for - how long have I been saying that?" Obama quipped.