Mitt Romney, who scraped out an eight-vote margin of victory in the Iowa caucuses on Tuesday, is looking to put the race for the GOP nomination to rest early in the calendar, but his rivals are piling on criticism in an effort to slow his momentum. As Peter Wallsten and Philip Rucker reported:

Fresh off the slimmest of victories in the Iowa caucuses, Mitt Romney landed here Wednesday and immediately faced intense attacks from Republican presidential rivals who vowed to challenge him more aggressively.

Newt Gingrich held a news conference in Concord to say that Romney is a liberal and a political chameleon, willing to change positions to suit his needs.

Jon Huntsman Jr. dismissed Romney’s newfound support from Sen. John McCain (Ariz.), saying that “nobody cares” about his backing or any of the other high-level endorsements the former Massachusetts governor has received.

And Rick Santorum, who fell just eight votes short of beating Romney in Iowa, said in an e-mail to supporters that Romney is a “bland, boring career politician who will lose to Barack Obama.”

Romney, considered a heavy favorite to win Tuesday’s primary in New Hampshire, sought to dominate the kickoff news coverage and further solidify his standing with GOP voters. He appeared at a midday town hall meeting with McCain to accept his endorsement.

“New Hampshire is the state that will catapult him to victory in a very short period of time,” said McCain, whose win in this state’s primary four years ago had that effect on him.

The focus on Romney came as one of the Republican field’s most vocal conservatives, Rep. Michele Bachmann (Minn.), announced that she was dropping out after her sixth-place finish in Iowa — further narrowing the group seeking to challenge Romney for the party mantle.

Newt Gingrich, who has pledged to draw a sharp contrast with Romney, has released a new ad attacking Romney for being timid. As Rachel Weiner explained :

No more Mr. Nice Guy (even if he was never all that nice). Former House speaker Newt Gingrich is out with his first ad attacking former Massachusetts governor Mitt Romney:

The spot, “Timid vs. Bold,” will start airing in New Hampshire and South Carolina within 48 hours. The Gingrich campaign calls the ad buy “significant.”

“Romney’s economic plan? Timid,” the narrator says. “Parts of it virtually identical to Obama’s failed policy. Timid won’t create jobs. And timid certainly won’t defeat Barack Obama.” The ad also praises Gingrich’s jobs plan as “a powerful plan for growing our economy and creating jobs.”

It’s not nearly as harsh as some of the attacks on Gingrich from the pro-Romney super PAC Restore Our Future. But Gingrich supporters have their own super PAC, Winning Our Future, which will go on the air in the coming days.

After pledging to run a positive campaign, Gingrich pledged last night to draw a “direct and sharp contrast” with Romney.

Romney has reserved some of his harshest criticism for President Obama, and on Thursday morning he took up former candidate Rep. Michele Bachmann’s charge that Obama is a ‘crony capitalist’. As Philip Rucker reported:

Mitt Romney labeled President Obama a "crony capitalist” during a campaign event here Thursday morning, accusing the president of engaging in “political payback” to the labor unions that have supported his campaigns.

 Seizing on Obama’s decision to install three appointees to the National Labor Relations Board without Senate approval during the congressional recess, Romney ratcheted up his rhetoric on labor relations.

 The establishment front-runner for the Republican presidential nomination used the phrase “crony capitalism” – a rallying cry for tea party activists frequently invoked by former Alaska governor Sarah Palin and Rep. Michele Bachmann (R-Minn.) – at least four times.

   “This is crony capitalism,” Romney said. “It scares away real entrepreneurs and investors. They go to other countries. It’s killing jobs. This president is a crony capitalist. He’s a job killer.”

Responded Obama campaign spokesman Ben LaBolt: “This is a bold statement from a governor whose state was 47th out of 50th in job creation during his tenure and a corporate buyout specialist who enriched himself by bankrupting companies and outsourcing jobs.” 

“While the president is fighting to ensure that hard work and responsibility are rewarded, and that everyone from Main Street to Wall Street plays by the same set of rules, Mitt Romney is willing to settle for an economy where fewer people succeed no matter how hard they work,” LaBolt said.

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