The primary season came to a close last night. Scott Brown won easily in the New Hampshire Senate primary, and two women won gubernatorial primaries in Massachusetts and Rhode Island.

But the upset of the evening occurred in Massachusetts 6 where 9 term incumbent John Tierney was defeated hadnily by Marine Corps veteran Seth Moulton. Tierney had been plagued by family ties to a gambling scandal and Republicans were hoping to run against him. Instead, Moutlon will square off against the openly gay Republican minority leader of the Massachusetts Senate Richard Tisei in November.

Politico:

Tisei narrowly lost to Tierney, who’s been plagued by a gambling scandal involving his wife and brother-in-law, in 2012. Although the race is still expected to be close, Moulton backers have argued he’s a better candidate to take on Tisei than the scandal-ridden Tierney.

In prepared victory remarks, Moulton called his win a reflection of voter disgust with Washington gridlock, and he vowed to keep the seat for Democrats.

“I look forward to contrasting our vision with that of Richard Tisei’s,” he said. “We won’t get fresh thinking and new leadership by sending someone to Washington who was first elected to office when I was just six years old.”

Tisei has already previewed his line of attack against Moulton, arguing that he’s likely to vote the same way as Tierney in Congress. Tisei also plans to pitch himself as a rare Massachusetts voice in the all-but-certain GOP House majority.

But Democrats say that’s a smokescreen — and that Republicans were hoping a weakened Tierney would win.

“Seth Moulton is a compelling general-election candidate who comes without the ethical questions that surrounded Tierney,” said a Democratic strategist, granted anonymity to discuss the race candidly. “Even Republicans have conceded that they wanted to run against Tierney because they don’t have a case to make against Moulton.”

Tierney’s loss makes him the fourth House incumbent – and first Democrat – to lose a primary this cycle. The others are GOP Reps. Ralph Hall, Kerry Bentivolio and Eric Cantor, who has since resigned. It’s also the first time an incumbent has lost a primary for a Massachusetts House seat since 1992.

Tisei came within a whisper of defeating Tierney in 2012 when the gambling scandal first broke. This race is likely to be close as well, although Moulton will have the wind at his back considering the huge disparity in Democratic registration in the district.

But the NRCC has named Tisei a "Young Gun" and is likely to support him with field workers and money. The Republican already owns a near 2-1 advantage of cash on hand so at the very least, Tisei is going to make Massachusetts 6 a competitive race.