GOP 2012: And they're off

The race for the Republican presidential nomination is beginning in earnest, as long-rumored candidates begin to get serious about their campaigns.

Seven candidates — a number of the top contenders among them — have announced campaigns for the GOP nod in 2012 or have formed exploratory committees. And the rest of the field could well be set in a matter of weeks, not months.

Former Massachusetts Gov. Mitt Romney used his first major public event since setting up his exploratory committee to address his healthcare plan in Massachusetts, a political albatross that threatens to weigh down his bid for the nomination.

He said he wouldn't apologize for the plan, which resembles President Obama's healthcare reform law in some important ways: namely, the individual mandate to purchase insurance.

"I presume that a lot of folks would think that if I did that, it would be good for me politically," he said. "But there's only one problem with that: It wouldn't be honest."

While Romney sought to defuse conservative opposition to his healthcare plan, he got more competition in the Republican primary from former House Speaker Newt Gingrich (Ga.) and Rep. Ron Paul (Texas), each of whom formally entered the race this week. Paul announced Friday morning on "Good Morning America."

After having flirted with running in the past four election cycles, Gingrich finally pulled the trigger and said he's running for president. And he's getting serious quickly; the former Speaker will outline his "Gingrich Jobs and Prosperity Plan" on Friday during a speech in Washington, before heading next week to Iowa, which hosts the nation's first nominating contest.

Paul, meanwhile, said that he'd make a second attempt at winning the GOP nomination after announcing his exploratory committee just over four weeks ago.

Paul has hired staff and opened an office in Iowa and raised over $1 million in 24 hours with an online "money bomb."

Gingrich and Paul join Romney, former Minnesota Gov. Tim Pawlenty, former Sen. Rick Santorum (Pa.), pizza magnate Herman Cain and former New Mexico Gov. Gary Johnson as candidates who have jumped in the race or formed exploratory committees.

It might not be too long until they find themselves with more company. The 2012 campaign got under way later than any recent presidential cycle, but the field could have even more entrants in the next few weeks.

Indiana Gov. Mitch Daniels (R), who's toying with running, said last Friday that he'll decide on running within weeks. His wife, Cheri, delivered a rare, closely watched public speech on Thursday evening that observers hoped would offer hints as to whether her husband would run. But she hardly addressed politics during her speech at a state GOP dinner.

"If you came here tonight expecting that, I'm sorry to report that you will be disappointed," she said.

Jon Huntsman, a former Republican governor from Utah, stepped down as Obama's ambassador to China at the end of April and has been testing the waters and adding staff since then. In his first interview since leaving office, Huntsman told Time magazine that he'll "let the rest of the month play out," suggesting that his decision could come in June.

Rep. Michele BachmannMichele Marie BachmannKlobuchar urges CNN town hall audience: 'That's when you guys are supposed to cheer, OK?' Michele Bachmann praises Trump: Americans will 'never see a more godly, biblical president' Will Biden lead a 'return to normalcy' in 2020? MORE (R-Minn.), a Tea Party favorite, has also expressed interest in running and has said she could make a decision by June.

Even Donald TrumpDonald John TrumpTrump watching 'very closely' as Portland braces for dueling protests WaPo calls Trump admin 'another threat' to endangered species Are Democrats turning Trump-like? MORE, the real estate mogul and host of NBC's "The Apprentice," has said he'd announce his intentions in early June. Trump visited New Hampshire, which hosts the nation's first primary, this week for the second time.

But the field is far from being complete. Arguably the two biggest question marks come from the race's biggest would-be candidates.

Former Arkansas Gov. Mike Huckabee, who won the Iowa caucus in 2008, has said he'll decide sometime this summer about whether he's running, but hasn't been much more specific than that. His team has worked hard to keep his name in the active conversation about potential candidates, especially since, at the moment, he's at or near the top of most national polls testing Republicans' preference in the nominee.

Former Alaska Gov. Sarah Palin (R), the 2008 GOP vice presidential nominee, has not provided many clues as to whether she'll seek the presidential nomination this time around.

Over the past month, Palin has given heavily promoted speeches in Wisconsin and Colorado, hinting that she might run. But she has continuously said that it's too soon to jump in the race.

"I still think that it's too early, though, a year and a half out," she said Wednesday on Fox News, where she remains a paid contributor. "I think it's too early to throw my hat in the ring, and I know that other potential candidates are thinking along those same lines."

Republican strategist Ford O'Connell, who worked for John McCainJohn Sidney McCainThe Hill's Morning Report — Recession fears climb and markets dive — now what? Trump makes rare trip to Clinton state, hoping to win back New Hampshire Graham promises ObamaCare repeal if Trump, Republicans win in 2020 MORE's 2008 presidential campaign, said that while the field is beginning to come together, the decisions of several candidates on the sidelines will help define the primary slate.

"I think it's starting to gel, I just think that some of the people aren't in the race," said O'Connell.

The eventual Republican nominee will come from a pool of candidates "with credible executive experience who can speak to multiple issues headlined by the economy, and who can answer the 3 a.m. call," he said, naming Huckabee, Huntsman, Daniels, Romney and Pawlenty as contenders who fit that description. Only two have taken formal steps toward running.

O'Connell said that the field likely won't be finalized until the Ames, Iowa, straw poll in mid-August.

"They all need to be in the field if you are fine-tuning the message to beat Obama," he said.