CEDAR RAPIDS, IOWA — Facing fresh polls showing their leads in Iowa disappearing, Democratic presidential candidate Hillary Rodham Clinton and Republican Mitt Romney rolled out new campaign tactics Sunday in an aggressive push to regain lost momentum.
Sen. Clinton of New York, who until recently would not even mention her rivals by name, used a news conference to question the ethics, character and "courage" of Illinois Sen. Barack Obama, employing the most pointed language she has used in the campaign.
Romney announced that he would deliver a speech Thursday on religion, a subject that he has been reluctant to touch despite growing signs that voters are leery of putting a Mormon in the White House. As recently as last week, Romney's eldest son, Tagg, said in an interview that he was beseeching his father to give such a speech but had yet to persuade him.
The steps reflect the rapidly shifting dynamics in Iowa, whose caucus is set for Jan. 3. For months, both Clinton and Romney held strong leads in Iowa. But a Des Moines Register poll published Sunday showed that their advantage had collapsed. Romney was trailing former Arkansas Gov. Mike Huckabee, 24% to 29%. Clinton was in second place behind Obama, 25% to 28%.
Both Romney and Clinton would be shaken by a loss in this crucial state. Clinton has cast herself as the inevitable nominee, and a defeat here would shatter perceptions that she can't be stopped. Romney has spent heavily on campaign ads in Iowa, hoping for an early victory to impress Republican voters in other states, where he is not so well known.
That Romney and Clinton would shake up the playbook with the caucus just a month away underscores the worry in both camps.
"It's really without precedent," said Gordon Fischer, a former chairman of the Iowa Democratic Party. Fischer, who is backing Obama, said: "They're both very, very concerned. They were the front-runners who are no longer front-runners."
Romney's speech will lay out how his faith would "inform his presidency," his campaign said Sunday. It echoes an address given 47 years ago by John F. Kennedy about his Catholicism when he was running for president. The speech comes amid polling that shows conservative Christian voters beginning to coalesce around Huckabee, a Southern Baptist preacher.
A recent survey by Rasmussen Reports showed that 48% of evangelical Christians in the Iowa GOP supported Huckabee -- more than all the other candidates combined.
David Kuo, an evangelical Christian and former White House official for faith-based programs, said of Romney: "At the end of the day, the vast majority of evangelicals consider Mormonism to be a cult. And that's his big problem."
Romney has faced pressure to deliver such a speech from some in his family and other leading Mormons such as Sen. Orrin G. Hatch (R-Utah). They have argued that Romney might lose the nomination if he fails to convince religious Christians that a Mormon is one of them.
Clinton, after a campaign rally urging Iowans to go to the caucus, said at a news conference that she would spend much of the next four weeks alerting voters to what she cast as a troubling gap between Obama's high-minded rhetoric and his political performance.
"Well, now the fun part starts," Clinton said. "We're into the last month, and we're going to start drawing a contrast, because I want every Iowan to have accurate information when they make their decisions."
Within hours of Clinton's news conference, Obama issued a statement saying: "This presidential campaign isn't about attacking people for fun. It's about solving people's problems, like ending this war and creating a universal healthcare system."
Clinton mentioned a pair of issues that she said undermined Obama's claim that he would practice a nobler form of politics: his healthcare proposal and his management of a special fundraising committee.
Obama, she said, has made conflicting statements about whether he is offering a healthcare plan that is truly universal in coverage. And one of his fundraising committees, Hopefund, has been giving money to politicians in states that hold the earliest contests in the 2008 election, in what she called a possible violation of Federal Election Commission laws.
"You can't get a straight answer [from Obama] on healthcare," she said. "Someone who runs on ethics and not taking money from certain people is found out to have at least skirted, if not violated, the FEC rules and used lobbyist and PAC money to do so."
She added that the difference between them was one of character.
"It's beginning to look a lot like that," she said.
Countering the charges at a news conference of his own in Des Moines, Obama said: "I think that folks from some of the other campaigns are reading the polls and starting to get stressed and issuing a whole range of outlandish accusations. Everything that we've done is in exact accordance with the law."