On the frozen morning after Christmas, Mike Huckabee waded into the knee-high grasses here and raised his camouflage 12-gauge shotgun toward a pheasant.
A blast cracked across the icy hills of this southern Iowa farm town. It might as well have been the starting gun for the sprint to caucus night. With a week until the first major test of the primary season, presidential candidates returned to the campaign trail after the holiday with guns blazing – turning up their rhetoric, launching new ads, and striking an increasingly bellicose tone.
Former Massachusetts Gov. Mitt Romney lashed out at Sen. John McCain over his immigration record, while Senator McCain accused Mr. Romney of flip-flopping. Sen. Hillary Rodham Clinton of New York issued a statement titled "I've Switched to Hillary," about a former Barack Obama supporter in Iowa who had changed allegiances. Senator Obama fired back with one about a former Clinton supporter now backing him.
And in leading reporters across a field in hunter's orange, Mr. Huckabee was taking a jab at Romney, who has drawn criticism for overstating his hunting experience and falsely claiming earlier this month that he had been endorsed as a gubernatorial candidate by the National Rifle Association (NRA).
"It has everything to do with running for president," Huckabee said of hunting before heading into the switchgrass with an NRA official. "You prove that you can shoot, and if somebody really messes with you with negative campaign ads, they just need to be prepared."
The Romney campaign had aired ads in Iowa this month attacking Huckabee on illegal immigration. After laying three dead pheasants in the snow, Huckabee joked, "Don't get in my way. This is what happens."
The home stretch before the Jan. 3 caucuses could prove pivotal in what remains an open race. Clinton and Obama are neck and neck in recent polls of Democratic caucusgoers, with former Sen. John Edwards close behind. Among Republicans, Huckabee has maintained a narrow edge over Romney, who has seen a comfortable lead dry up in recent weeks.
Analysts say the Iowa contest carries the greatest significance for Mr. Edwards, who has been campaigning in the state since the 2004 primaries and who would be unlikely to outlast anything short of a first-place finish.
The start of the final week has seen candidates cramming their schedules with events across the state and driving home campaign themes, all with an eye to churning enough excitement to drive supporters to the caucus sites. Appearing with her husband, former President Bill Clinton, and daughter in Iowa Wednesday, Clinton cast herself as the only candidate with the experience to bring about change. Obama was expected to lay out his closing argument to Iowans at a Des Moines speech Thursday.
"There's an old phrase that the key to success in the caucus is organize, organize, organize and get hot at the end," says professor Dennis Goldford, of Drake University in Des Moines. "You're getting close to the point where it's less about making a new sale, than making sure people already committed to you turn out."
A lot can change in the countdown to caucus night, he says. John Kerry's campaign was faltering in late December 2003 before missteps by Howard Dean and new television ads meant to soften the Massachusetts senator's image helped catapult him to first place here.
Mr. Dean, who had earlier appeared to be surging, drew media coverage for an "Adopt an Iowan" program in which supporters sent hand-written notes to voters in the Hawkeye State. He still finished third. The run-up to the caucuses, says pollster Dick Bennett, is when "we begin to see if the candidates really do have the organization they say they do."
In recent days, the candidates have not only faced attacks from each other. The pro-business Club For Growth announced Wednesday that it is buying $175,000 in Iowa television ads condemning Huckabee's tax record as Arkansas governor. On Thursday, some 22 talk-radio hosts from around the country were expected to converge on Des Moines for a marathon broadcast sponsored by The Federation for American Immigration Reform, a group critical of the bipartisan immigration measure backed by the Bush administration earlier this year.
Several candidates are launching bus tours across Iowa this week, while others, such as former New York Mayor Rudolph Giuliani and McCain, continue to focus efforts in other early-voting states, where their poll numbers are higher.
For Iowa voters, the crush of attention in the final weeks is both exhilarating and wearying. Joan Brown, a retired hairdresser from St. Charles, says she has gotten three to four phone calls a day from campaigns seeking her support.
"When it becomes annoying is when they call at 6 p.m. when you're having dinner or at 10 p.m. when you don't want to talk anymore," Ms. Brown, a Democrat, said Wednesday night while waiting for Clinton to appear at a campaign stop in Cumming, Iowa. "You don't want to hear it again, but, you know," she added, shrugging, "it's only every four years."
• Staff writer Linda Feldmann contributed reporting from Washington.