Richard Tisei was in the perfect position to become the first Republican elected to Congress from Massachusetts in 20 years.

The openly gay, happily married former state legislator is running in the most conservative congressional district in the Bay State—albeit one that Barack Obama still won by 11 points in 2012—in a low turnout off-year with a popular Republican gubernatorial candidate at the top of the ticket. And if Tisei were to pull out a win, he would be the first non-incumbent openly gay Republican to win election to Congress. (Two former congressmen, Jim Kolbe of Arizona and Steve Gunderson of Wisconsin, were outed in the 1990s as incumbents and won re-election.)

Plus, Tisei looked like he was getting a rematch against John Tierney, an ethically questionable nine-term incumbent Democrat whom Tisei almost bested in 2012.

But then Tierney lost his primary.

Tisei is now facing off against Seth Moulton, a relative political novice with a Harvard degree. Moulton also spent four combat tours in Iraq as a Marine officer, but has underplayed his service, explaining to the Boston Globe that there is “a healthy disrespect among veterans who served on the front lines for people who walk around telling war stories."

And so, for Tisei, this election looks far more difficult than he’d originally expected. Tisei’s entire campaign was based on running as an alternative to Tierney, whose wife and brothers-in-law were convicted of tax fraud relating to an offshore gambling ring. Although Tierney was never directly tied to the gambling ring, there were questions about whether he was aware of his family’s involvement.

As a result of the scandal, in 2012, with Barack Obama at the top of the ticket, Tierney barely won a one-point squeaker over Tisei. Now, instead of attacking Tierney as a corrupt Washington insider, Tisei supporters are attacking Moulton as the type of cynical pol who doesn’t represent the real values of a coastal district that stretches from Boston’s northern suburbs to the New Hampshire border.

And Moulton’s camp is returning the favor.

Kirsten Hughes, the chairman of the Massachusetts Republican Party, noted that Moulton has “fewer ties to the district” than Tisei and described him as part of “the go along, get along crowd… enticed by the lure of Washington.” In contrast, Carrie Rankin, a campaign spokesperson for Moulton, attacked Tisei as “a career politician with 30 years in elected office,” while insisting that Moulton brought “fresh perspective and a new approach to leadership.”

But it’s unclear how much these attacks have succeeded with voters. As one national Republican strategist told The Daily Beast, the race “reset” when Moulton won the primary in September. The result was that, with less than two months left before Election Day, most voters in the district have had little time to learn about the 36-year-old first-time candidate, and it was difficult for a narrative to set in.

Polling in the district has been mixed. Republicans touted a recent poll from Emerson College that had Tisei up two points (PDF) while Democrats pointed to a month-old poll from WBUR that had Moulton up by eight. Further, a Democratic operative familiar with the race pointed to more recent internal polling which the operative claimed had Moulton up by double digits and with very high favorable ratings. Outside observers like Cook Political Report view the district as “leaning Democrat.”

But while an openly gay Republican winning a Congressional seat might be big news nationally, in Massachusetts the victory might be more historic for his party orientation and than his sexual orientation. The deep blue state has been loathe to elect Republicans to Washington, D.C., and a Tisei win would be a jolt to a state GOP that has not won a November federal election since the Republican wave of 1994.

But the odds seem to be increasingly against Tisei. While a Republican might be able to get lucky enough to triumph over a scandal tarred incumbent in Massachusetts, beating a combat-decorated Marine may be a bridge too far.