MANCHESTER, New Hampshire – If Mitt Romney wins the Republican nomination and competes in this state in the general election, one of his chief critics is likely to be a man whose political rise Romney unintentionally helped launch: Massachusetts Governor Deval Patrick.

In 2006, Romney, who was elected governor of Massachusetts in 2002, opted against running for reelection. He risked losing in heavily-Democrat Massachusetts and winning reelection likely would have required Romney to take stances that would have hurt his chances of winning the Republican nomination in 2008.

So six years ago, Patrick ran in an election with no incumbent, and using the same kind hope and optimism rhetoric President Obama relied in 2008, became only the second African-American ever elected governor of a state. (Virginia’s Douglas Wilder was elected in 1989; other black governors, such as New York’s David Patterson, were not directly elected.)

Now, Patrick may be in a unique position to help Obama in November. He is very close to New Hampshire, a key swing state that the president would like to keep in the Democratic column.

More importantly, Patrick could emerge as a key campaign surrogate on television, a person with perhaps more knowledge of Romney’s record than any Democrat in the country. He could highlight what many Democrats view as the chief vulnerability of Romney: his record of inconsistency on some key issues.

Patrick has effectively been in charge of implementing the health care law Romney signed in Massachusetts, which Romney has subsequently distanced himself from after President Obama used it as a model for a national health care bill.

In an interview last year on MSNBC, Patrick said he had doubts about the “individual
mandate,” the requirement in both the Massachusetts and federal laws that every person purchase health insurance, a provision opposed by many conservatives. Patrick claimed Romney’s comments about the idea helped convince him to support the mandate, a kind of damning praise Patrick is likely to use again.

For Patrick, a prominent role in the Obama campaign could have its own benefits. Patrick has denied any interest in a presidential run himself, but many politicians later reverse themselves on that.

Patrick, whose second term ends in 2014, was rumored as a potential candidate for attorney general after Obama was first elected and could be tapped for that post after his run as governor if the president wins a second term.

Follow Perry Bacon Jr. on Twitter at @perrybaconjr