Is this Rep. John Tierney's last stand?

SALEM, Mass. -- It shouldn't be this difficult for a nine-term incumbent Democrat in a safe Democratic district: in a span of 8 weeks, Rep. John Tierney, D-Massachusetts, is facing a serious primary challenge and, if he survives, a potential toss-up general election.

Tierney faces four challengers in the Democratic primary Tuesday but one, Seth Moulton, a 35-year-old former Marine who served four tours in Iraq and earned three degrees from Harvard, has mounted a challenge so serious that Tierney bought last-minute TV ad time to try to brush him back.

The race, considered one of about a dozen Democratic House toss-up races, is picking up competitive momentum, with recent polling showing Moulton closing the gap with Tierney.

If Tierney is victorious Tuesday, he then has to turn right around and face Republican Richard Tisei, the former state Senate minority leader, who lost to Tierney by less than 4,000 votes in 2012, a year when President Obama's 61 percent of the vote in Massachusetts likely benefitted Tierney.

Tierney, who has been dogged by questions for years about his wife's legal woes and what he knew about it (she pleaded guilty in 2010 to filing false tax returns for her two brothers who were involved in illegal gambling), touts his 17 years on Capitol Hill as an asset.

"I am the only one of the group who is running that can saw you know we have had experience with that and we get things done and you don't want to be starting a ground zero if you don't have to," Tierney told CBS News while visiting a fire station in historic Salem, which is about 15 miles north of Boston. "This is a body where experience and seniority really matters."

But both the Boston Globe and Boston Herald editorial boards, which rarely agree on anything, endorsed Moulton, both mentioning the scandal in their endorsements and both saying it's time for a change.

To George Gray, an Ipswich resident and retired college professor, the memories of Tierney's wife's scandal linger but what matters more now is Tierney's continued inability to get things done.

"Has he done anything?" Gray responds, eyebrows raised, when asked if he has seen any of Tierney's work on education policy come to fruition.

Both Moulton and Tisei are taking the outsider's approach, also arguing it's time for change and each saying they're the right person to help get things done in Washington.

"I was in Najaf in 2004 exactly 10 years ago today and a young guy in my platoon looked up at me and he said you know, sir, you ought to run for Congress one day so that this does not happen again," Moulton told CBS News while campaigning at the Ugly Mug Diner in Salem. "Washington is broken," he said, adding that it is time for a new generation in Congress.

"I think people are ready for a change," but he added, "this is Massachusetts," asserting that the state's sixth congressional district congressman should be a Democrat.

As an openly gay Republican, however, Tisei has a unique appeal in Massachusetts, the first state to legalize same-sex marriage.

"I wouldn't be able to probably run in a lot of areas in the country in districts as a Republican being openly gay around the country so I am really thankful for where I live and it is something I think on a national level that I can bring I don't just want to help change the country, I want to help change the Republican party and help bring them back to their roots and something that is a proponent of civil rights and trying to make the tent bigger," Tisei told CBS News during a campaign stop at the Lynn Senior Center.

Tisei is also convinced that change is necessary, saying that he is "running to save the country" and having a voice in the majority will benefit the people of the sixth district.

Tisei has fans who are not only frustrated with Washington but also frustrated with President Obama. Judy Marcus, a 73-year old registered independent who lives in Lynn, a city of about 90,000 located just north of Boston, is "extremely disillusioned with what is going in at the top," adding "Obamacare was a disaster."

In terms of working across the aisle, Tisei is in a tricky position because the district is mostly Democratic and whoever wins Tuesday's Democratic primary is sure to paint Tisei as a potential lackey of House Speaker John Boehner, R-Ohio.

"I am fed-up with John Boehner's Congress," Tierney said. "But my task is reminding people that there is a difference when Democrats are in charge and Republicans are in charge, a difference when a Republican holds a seat and a Democrat holds a seat."

When asked if he is excited to work with Boehner, Tisei voiced willingness to work with both sides.

"So yeah I think that the speaker, I will work with, you know, [House Minority Leader] Nancy Pelosi, if anybody has a good idea," Tisei said.