Rep. Michele Bachmann (R-Minn.) endorsed former Massachusetts governor Mitt Romney in Virginia on Thursday.

“I'm honored to announce that today, I am endorsing Governor Mitt Romney for President of the United States, a man who will preserve the American dream of prosperity and liberty,” she said in a statement released this afternoon.  “On November 6th, the only option is Mitt Romney for President.”

Rep. Michele Bachmann (R-Minn.) will endorse Romney today. (Chris Carlson/AP)

The conservative lawmaker and former White House hopeful was one of Romney’s harshest critics in the presidential race. She dropped out in early January after placing sixth in Iowa’s caucuses; since then she has issued vague calls for unity, but stopped short of an endorsement.

Bachmann based her campaign on opposition to Democratic health-care reform and repeatedly argued that Romney was too close to President Obama on the issue. In December she called Romney“the only governor in the history of the United States to put into place socialized medicine.”

Shorly before exiting the race, Bachmann told ABC News that Romney, who was governor of Massachusetts from 2003 to 2007, “can’t beat Obama” because he wrote “the blueprint for Obamacare.”

Now, all of Romney’s rivals save Rep. Ron Paul (R-Texas) have dropped out, and Bachmann has decided that time to embrace Romney has arrived. Former Bachmann campaign manager Keith Nahigian said there was also a personal element to the endorsement.

“She really liked Romney during all the debates. Really liked him behind the stage, behind the scenes,” Nahigian told MSNBC. “He was so polite to her every time they saw each other.”

Endorsements rarely mean much in poll numbers, but Bachmann’s seal of approval is a sign that tea party Republicans have come around to the presumptive nominee.