Romney's announcement came after an unannounced visit to the University of New Hampshire, where he says he spoke with students about the economy.
"From my vantage point in business and in government, I have become convinced that America has been put on a dangerous course by Washington politicians, and it has become even worse during the last two years. But I am also convinced that with able leadership, America's best days are still ahead," Romney said.
"That is why today I am announcing my exploratory committee for the presidency of the United States. It is time that we put America back on a course of greatness, with a growing economy, good jobs and fiscal discipline in Washington."
Romney also tested a theme for his would-be campaign, saying: "I believe in America." It's a subtle response to Obama's 2008 campaign message of, "Change you can believe in." It was also the subtitle of his revised 2010 book, "No Apology."
"I believe in the freedom and opportunity, and the principles of our Constitution, that have led us to become the greatest nation in the history of the earth — and I believe that these principles will confirm American's future as well," he says."
In his announcement, Romney also mentions a trip to Nevada, another early nominating state and the only one of the first four where he notched a victory in his 2008 campaign. It is unclear to what extent he will contest the Iowa caucuses and South Carolina primary, where social conservatives have greater sway.
Unmentioned is what is likely to be his Achilles' heel as he appeals to a Republican electorate driven by distaste with the expansive federal government — the healthcare plan he signed into law as Massachusetts' governor, five years ago this week.
"When I served as governor of Massachusetts, I used the skills I had learned in 25 years in business to streamline state government, balance the budget every year, and restore a $2-billion rainy-day fund," he says of his one term.
Democrats have gleefully pointed to the fact that Romney's plan, like the one Obama signed, included a mandate that all of the Bay State's citizens have health insurance. Ahead of the anniversary of Romney signing the law, Democrats in New Hampshire plan a news conference to "thank Romney for providing the critical momentum necessary to get President Obama's vision of health reform through Congress and signed into law."
"It's obvious that Governor Romney … [is] going to have to confront the issue of the Massachusetts healthcare issue," Sen. John McCain (R-Ariz.), the party's 2008 nominee, told reporters last week.
Romney joins former Minnesota Gov. Tim Pawlenty as the two most prominent Republicans to form exploratory committees. Former House Speaker Newt Gingrich is also raising money under federal limits as he considers a White House run.
Romney won 11 nominating contests in his 2008 run, most notably Nevada's caucuses and the Michigan primary. He's remained politically active through his Free & Strong America PAC, supporting local and statewide candidates he will be courting again in his next campaign.