BOSTON — Massachusetts Republicans Mitt Romney and Scott Brown have a history of supporting each other throughout their political careers.
But with each facing a tough election, neither the presidential candidate nor the U.S. senator is playing up that history, perhaps with good reason.
Brown, trying to win re-election in one of the most Democratic states, spends much of his time promoting his bipartisan bona fides and describing himself as a "Scott Brown Republican" rather than a conservative or liberal Republican.
He may be one of the few Republicans running who boasts of working with President Barack Obama to pass bills. On his campaign website, Brown has posted pictures and videos of him with the Democratic incumbent.
Romney has moved increasingly to the right, shedding some of the more moderate positions he held as Massachusetts governor as he worked to rally GOP activists during the primaries.
Brown took a more moderate stance, alienating some of the conservative and tea party activists who helped elect him in 2010. Those are the same people Romney will need if he hopes to win in November. Brown's shift to the middle could make him a liability for Romney among conservatives.
Brown probably will continue to play down his ties to his former governor and emphasize his own independent streak, particularly with recent polls showing Obama enjoying a double-digit over Romney in Massachusetts.
"Brown sees pretty clearly that there are no Romney coattails in Massachusetts for him to ride and, indeed, being close to Romney for his own re-election bid could be a liability," said Paul Watanabe, a political science professor at the University of Massachusetts.
The distance between the candidates is more than strategic. Romney and Brown have adopted competing views on several big issues, from a new nuclear weapons treaty with Russia to the fate of the U.S. Supreme Court's Roe v. Wade decision legalizing abortion.
Romney has said Roe v. Wade should be reversed. Brown says a woman should have the right to an abortion, although he opposes federal money for the procedure. Brown voted for the new START treaty with Russia, saying it was important for national security. Romney said the treaty was Obama's "worst foreign policy mistake."
The differences don't stop there.
Romney has called for repeal of the Dodd-Frank financial overhaul law. Brown voted for it. Romney backs amending the Constitution to ban gay marriage. Brown opposes such an amendment and says gay marriage is "settled law" in Massachusetts. Such unions became legal in the state in 2003.
Romney, in 2007, said the military's "don't ask, don't tell" policy seemed to be working. Brown voted with Democrats and some Republicans to end the policy that barred gays from serving openly in the military, earning praise from the Log Cabin Republicans, a gay GOP group.
While Romney hasn't said if he'll release more than two years of his income tax returns, Brown has made public six years of his tax documents.
When pressed on the differences of opinion, Brown's campaign repeats his endorsement of Romney.
"Sen. Brown thinks Mitt Romney is a good and decent person who is devoted to his family and strong on jobs and the economy and that's why he supports him for president," Brown spokesman Colin Reed said in a statement.
The campaigns also share staff, including Eric Fehrnstrom, a top political adviser to both men. Fehrnstrom did not respond to a request for comment.
Romney and Brown come from very different backgrounds. Brown's parents divorced early and his family moved often when he was young. Romney's father was a governor of Michigan and an automotive executive. Still, the two found political common ground nearly a decade ago.
Both are ambitious Republicans from a state known for frustrating GOP hopes.
When a seat opened up in the state Senate in 2004, Brown, then a state representative, jumped into the race. The seat had been held by a Democrat but, with a campaigning and fundraising assist from then-Gov. Romney, Brown squeaked out a narrow victory over his Democratic challenger, who at first doubted the results.
"It's a new day in Massachusetts politics when the Democrats are calling for a recount," said Romney, who appeared at a Statehouse news conference with Brown after the election.
When longtime Democratic Sen. Edward M. Kennedy died of brain cancer in 2009, Romney supported Brown in the special election to fill the seat. Though Brown was considered a long shot, Romney issued campaign fundraising letters on his behalf.
"Scott's election would shock the country," Romney wrote. "Wouldn't it be nice to elect a fiscal conservative to Ted Kennedy's seat in the United States Senate?"
Romney had challenged Kennedy for the seat in 1994, and lost.
The mutual accolades reached a pinnacle at an annual meeting of conservative activists the month after Brown's election to the Senate.
Introducing Romney, Brown joked that at the start of his Senate campaign "I could have held my campaign rally in a phone booth" and Romney was "one of those guys who was in that phone booth with me."
Romney returned the compliment moments later.
"Scott Brown, boy, I'd take him anywhere I could take him," he told the crowd.
Except that neither has taken the other anywhere lately.
Democrats are busy trying to make voters aware of the ties between Romney and Brown, especially in Massachusetts, where Brown faces a tough fight against likely Democratic challenger Elizabeth Warren.
Democrats note that Romney and Brown both supported an amendment in the Senate this year that would have allowed employers or health insurers to deny coverage for services they said violated their moral or religious beliefs, including birth control. The amendment failed.
"Scott Brown and Mitt Romney have made clear that they share a close personal relationship as Massachusetts Republicans," state Democratic Party spokesman Kevin Franck said in a statement. "They share the same policy agenda of protecting tax breaks for big oil and millionaires, while refusing to invest in helping the middle class."