CLEAR LAKE, Iowa — Hillary Rodham Clinton suggested Monday that Barack Obama has too little experience and perhaps too much ambition, pressing an increasingly aggressive campaign against her chief rival for the Democratic presidential nomination.
Both candidates were in Iowa, one month before the nation's leadoff caucuses with new polls showing Obama had whittled away her early lead and they were virtually tied among Democrats in the state.
"So you decide which makes more sense: Entrust our country to someone who is ready on day one ... or to put America in the hands of someone with little national or international experience, who started running for president the day he arrived in the U.S. Senate," Clinton said.
Her rhetoric underscored the tightness of a race in which polls show a dead heat between them in Iowa, with former Sen. John Edwards of North Carolina also in strong contention. Many Iowa caucus goers say they still haven't made up their minds or could yet change them.
Clinton accused Obama of a "rush to campaign" in not returning to Washington this fall to vote on a resolution naming an Iranian military unit a terrorist organization. The Bush administration supported the measure, as did Clinton _ and Obama has criticized her for it.
"Presidents can't dodge the tough political fights," she said.
Obama spokesman Bill Burton retorted, "The truth is, Barack Obama doesn't need lectures in political courage from someone who followed George Bush to war in Iraq, gave him the benefit of the doubt on Iran, supported NAFTA and opposed ethanol until she decided to run for president."
As for when Obama decided to run, there was a lot of back-and-forth about that.
Over the weekend, the Clinton camp sent reporters a memo taking Obama to task for saying he hadn't been planning for years to run for president _ unlike "some of the other candidates."
On the contrary, the Clinton folks said, he'd made his plans clear to law school friends and even wrote an essay as a young child saying that was his ambition.
After an event in Iowa on Monday, Obama was asked to comment and said, "No."
But then he said, "It's silly season. I understand she's been quoting my kindergarten teacher in Indonesia." He then walked out of the room without responding to additional shouted questions.
Elsewhere in Iowa, Edwards mocked the Clinton campaign for sniping at Obama about his presidential ambitions.
"It's like, boy, you can tell you're getting close to the caucuses," said Edwards in Waterloo.
"I want to confess to all of you right now," Edwards said. "In third grade I wanted to be two things: I wanted to be a cowboy and I wanted to be Superman."
A new AP-Pew poll showed Clinton essentially tied with Obama in Iowa, 31 percent to 26 percent, with Edwards at 19 percent and New Mexico Gov. Bill Richardson at 10 percent.
Clinton's campaign events on Monday were all based encouraging voters to go to the Jan. 3 caucuses _ and to bring a buddy.
She held a campaign event at the Surf Ballroom at Clear Lake, the same hall where three Rock 'n' Roll legends performed before their death in a plane crash in February 1959.
"I am old enough to remember Buddy Holly, Ritchie Valens and the Big Bopper," Clinton told her audience. She said she felt like hearing Valens' "La Bamba."
She was late for the Clear Lake event after a campaign plane carrying reporters ahead of her remained on the runway after landing when the cabin began filling with smoke. The plane had to be towed off the runway before Clinton's plane could land. The source of the smoke was not immediately apparent, the pilot and campaign aides said.
"We were circling and circling and circling," Clinton said.
She pledged to be "a president who wakes up every morning ready to fight for our families ... and the causes we believe in. It's what I've been doing for 35 years."
While her husband Bill was president, she said, "we created" millions of new jobs during the 1990s.
The Iowa caucuses are Jan. 3, and New Hampshire votes Jan. 8. Several other states quickly follow, culminating in races on Feb. 5 when two dozen states hold contests.
Clinton is fighting to nurture a sense of inevitability and to stop Obama or Edwards from undercutting it with an Iowa victory.
Clinton assailed the Illinois senator on Sunday for a political action committee he controls that has contributed money to elected officials in early voting states. Obama has brushed off the criticism.
Later, in another campaign appearance in Sioux City, Clinton did not mention Obama or the tight competition among Democrats, instead appealing to members of the audience to show up at the caucuses.
"Caucusing, if you've never done it before, can seem a little daunting," she said.
Even later, wrapping up her campaign day with an early evening event in an aircraft hangar in Council Bluffs, Clinton said: "The eyes of the world are going to be on Iowa."
"I wish I was an Iowan" so she could participate herself in a caucus, she added.
Associated Press Writers Mike Glover and Amy Lorentzen contributed to this report.