KEOKUK, Iowa -- A voter in Burlington told me this morning she found Sen. Barack Obama's speech at the Catfish Bend Casino "much more forceful" than times she's seen him previously.

Obama (D-Ill.) summed up what he's hearing from chief rivals Sen. Hillary Clinton and former Sen. John Edwards, then dismissed their criticism.

First he noted that "some folks" have said - translation: former President Bill Clinton told Charlie Rose this month - that voting for Obama is like a "roll of the dice."

"The real gamble," Obama said today, is having "the same old folks do the same old thing and expect real results ... that's the definition of insanity."

He said he rejected the Clinton argument that she is more experienced because she knows "how to work the system," saying "We need to put an end to the game playing in Washington."

Moving on to Edwards, without mentioning his name, Obama said another argument against him is he is "too nice, not angry enough or confrontational enough" to take on special interests.

Obama rejected that too, suggesting that Edwards has only been talking about fighting for change while running for president, while for him, "It's not something I just started talking about ... I've been at it all my life."

About the only time he mentioned names was when citing polls that show he would "beat every single one of the Republican candidates" in a general election matchup. "John Edwards doesn't beat 'em all, Hillary Clinton doesn't beat them all," he said. "I beat them all."

Obama also had a new laugh line that some had wanted him to "kneecap" his rivals, that they said: "He's got to do a Tonya Harding on her." The audience cracked up.

Obama also has a newly designed - and very blue - Web site up today that lets you track him through Iowa.

Obama, Edwards and Clinton are locked in a near three-way tie before Iowa's caucus Thursday night, and have been going after each other (mostly without naming names) in their speeches as they travel the state and make closing arguments. I have a story up today from the campaign trail about their war of words. My story also highlights how many Iowans remain undecided.

Clinton took some heat earlier this week for not taking questions from voters after some of her Iowa speeches, and Edwards conveniently announced a new "Ask John" Web site where voters can ask him anything they want. He also takes several questions after each of his campaign speeches.

"If you have a question it is my responsibility to answer that question," Edwards said in Davenport Friday night, adding he wants to have "real interaction" with voters instead of "just a speech."

So it was notable that Obama has taken no questions at his first three events today in Burlington, Fort Madison and Keokuk.

Finally, American Research Group just released its latest Iowa poll:

On the Democratic side, Hillary Clinton leads with 31% followed by John Edwards and Barack Obama at 24% each. Clinton leads among women with 35%, followed Obama at 21% and Edwards at 20%. Edwards and Obama are tied among men at 28% each, followed by Clinton at 25%. 46% of Clinton supporters say Edwards is their second choice and 23% say Obama. 32% of Edwards supporters say Obama is their second choice, followed by Richardson at 19% and Clinton at 18%. 55% of Obama supporters say Edwards is their second choice, followed by 24% for Clinton. Majorities of supporters of the remaining candidates name candidates other than Clinton, Edwards, or Obama as their second choices. Over one out-of-five (21%) say they could change their minds between now and January 3.

-- Christina Bellantoni, national political reporter, The Washington Times