WASHINGTON (CNN) -- With Sen. Hillary Clinton coming off a strong fundraising quarter and new polls showing she is surging both nationally and in Iowa, her Democratic rivals are hoping to knock her off her stride, and Republicans are directing their fire at her in anticipation of a general election matchup.
Clinton is riding a political high less than three months before the Iowa caucuses. Last week, the New York Democrat reported raising $22 million for her primary campaign during the third quarter, outpacing her nearest rivals for the Democratic presidential nomination -- Sen. Barack Obama of Illinois by $3 million and former Sen. John Edwards by at least $15 million.
And on Sunday, a new Des Moines Register poll showed that Clinton is leading Edwards by 6 points and Obama by 7 points in the crucial early-voting state of Iowa, earning the support of 29 percent of the likely caucus-goers who participated in the poll.
"She's looking more inevitable, and the more inevitable she looks, the easier it is to raise money. People want to be with a winner," CNN's senior political analyst Bill Schneider said.
As Clinton hit the road Monday for her "Middle-Class Express" tour across Iowa, she continued her strategy of acting like the presumptive nominee and focused her rhetorical fire on President Bush rather than on her Democratic rivals.
"America's middle-class families have been invisible to the president," Clinton said. "It's as if he has looked right through them."
Edwards and Obama are hoping a Clinton stumble in the Iowa caucus, currently scheduled for January 14 but is likely to be moved to earlier in the month, could disrupt her at-the-moment smooth path to the nomination. Watch how Edwards and Obama are betting on Iowa »
Both Edwards and Obama have built Iowa organizations as good or better than Clinton's, and Clinton could be hurt by a second-place finish to either one of them.
"It's not 100 percent clear whether it's a Clinton-Obama or Clinton-Edwards race," CNN's Schneider said. "There is a Clinton vote and an un-Clinton vote, and right now, that looks to be Obama, but it could be Edwards if he wins the Iowa caucuses."
Clinton's rivals are also taking more rhetorical shots at the New York Democrat, knowing that they must raise doubts in Democratic caucus-goers and primary voters about her ability to win and to deliver on key issues, such as the war in Iraq, if they are to have a shot.
On Monday, Obama tried to argue that what many view as one of Clinton's received strengthens -- her Washington experience -- was actually a liability.
"There are some in this race who actually make the argument that the more time you spend immersed in the broken politics of Washington, the more likely you are to change it. I always find this a little amusing," Obama said during a speech in Portsmouth, New Hampshire. "I know that change makes for good campaign rhetoric, but when these same people had the chance to actually make change happen, they didn't lead."
Edwards has also continued to attack Clinton on what many political observers viewed as one of her greatest weaknesses going into the primary fight -- her position on Iraq.
On Sunday, Edwards argued that Clinton was not committed to ending the war. Clinton has said she would withdraw a "vast majority" of the combat troops from Iraq but would leave some troops to conduct anti-terrorists operations.
"To me, that is a continuation of the war, and this war needs to be brought to an end," Edwards told Tim Russert of NBC News.
Edwards said he would withdraw all combat troops from Iraq and position a quick reaction force in Kuwait to combat al Qaeda.
"I want to be able to say next fall, when I'm the Democratic nominee, and I'm standing with the Republican candidate, that Americans have a very clear choice," Edwards said. "They can choose a Republican who wants to continue the war or a Democrat who wants to end the war. We can't just be a little bit better than them. We have to be very clear that voters have choices in this election."
Clinton has even drawn the attention of the Republicans, who are hoping to define the issues they would run on against her if she becomes the nominee.
After a Democratic debate last month in which Clinton said she would support an absolute ban on the use of torture during the interrogation of terrorist suspects, former Massachusetts Gov. Mitt Romney, a Republican presidential candidate, blasted her for showing "a fundamental weakness when it comes to our country's national security."
And fellow Republican presidential candidate Rudy Giuliani criticized Clinton for her proposal to offer a $5,000 "baby bond" from the government to help pay for future costs of college or buying a home, saying that the cost, $20 billion in his estimate, would be too much.
"Hillary, that's real money," Giuliani added. "You and Bill can't afford that. It's got to come out of somebody's pockets. You know who it comes out of?"
Even the Republican National Committee has cited her fundraising "juggernaut" in efforts to rally support.
In a fundraising e-mail sent last week, the RNC told supports that the Clinton "is crisscrossing the country raising tens of millions of dollars from Hollywood elites, Big Labor and trial lawyers." E-mail to a friend
CNN's Candy Crowley, Mark Preston and Scott Anderson contributed to this report.