Bachmann and Romney in September (Joe Raedle/Getty Images)
In a statement, the Minnesota congresswoman said she was "honored" to back Romney, describing him as "a man who will preserve the American dream of prosperity and liberty."
She later appeared with Romney at a campaign event in Portsmouth, Va., where she said she was thrilled to introduce "our president."
"I think for all of America, this is a very simple proposition this November: President Barack Obama or President Mitt Romney?" she said. "Very easy."
A tea party favorite, Bachmann ended her own run for president in January, after she placed a disappointing sixth place in Iowa's Republican presidential caucuses. While Romney had lobbied Bachmann for her support for months, she held out, telling reporters in recent weeks that she would endorse on her own timetable, not others'.
While Bachmann emphasized in her decision to back Romney, Democrats are already revisiting the pointed attacks she lobbed against the former Massachusetts governor during the heated GOP primary. In pressing her own case to be the nominee, Bachmann frequently offered the most scathing critiques of Romney of anybody in the GOP field, insisting repeatedly that he could not beat Obama.
"The signature issue of Obama is 'Obamacare.' You can't have a candidate who has given the blueprint for Obamacare. It's too identical. It's not going to happen," Bachmann told ABC News in January. "We have to have a candidate, a bold, distinct candidate, in the likeness of Ronald Reagan."
But on Thursday, she backed off that claim. Joining Romney and Virginia Gov. Bob McDonnell on stage, Bachmann declared, "This is what victory looks like."
While Romney had hoped Bachmann would come off the bench to help him woo conservatives in the heat of the GOP primary, she still has the potential to aid his campaign by convincing social conservatives and other Republicans skeptical of his bid to turn out this fall and vote.
In an interview with CNN last week, Bachmann suggested she was already doing just that, telling the network she had been "working behind the scenes, bringing together all factions of our party" to boost Romney's efforts to beat Obama in November.
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- Politics & Government
- Mitt Romney
- Michele Bachmann
- President Barack Obama