NEW BEDFORD, Mass. (WPRI) — Democratic Congressman Bill Keating could face a primary next year from the northern edge of his district.

Norwell Selectman Joe Rull, a veteran of Boston city politics, confirmed Tuesday he is actively considering a 2020 run for the 9th Congressional District seat held by Keating, who was first elected in 2010.

“It’s too early to decide, but I’m definitely thinking about it,” Rull told WPRI 12. “I care deeply about the constituents. … It’s just right now I don’t know if this is the right time. It’s very early on.” He said he disaffiliated from the Democratic Party during the last election cycle but would run in the party’s Sept. 15 primary if he jumps into the race.

Still, Rull declined to disparage the incumbent directly. “I’m not going to criticize Congressman Keating — he’s done a good job,” Rull said. “It’s just something I’ve always had an eye and a love for government and politics, and I want to continue that.”

“It’s more about the voters and how they feel — if we can get more out of our Congress,” he said, citing gun violence as a top concern.

Rull is close to Boston Mayor Marty Walsh and served as one of his top aides until 2015, when he joined the short-lived effort to bring the Olympics to Boston. Rull also worked for Walsh’s predecessor, Mayor Tom Menino.

The 9th District stretches down the South Shore into the cities of Fall River and New Bedford and out to Cape Cod and the Islands. Keating keeps a relatively low profile compared to the two congressmen whose districts border his, Joe Kennedy III and David Cicilline, but won an easy re-election victory last year against a well-funded Republican challenger.

Keating will also start the election cycle with plenty of cash: he had more than $1.4 million in his campaign account as of June 30, according to the Center on Responsive Politics. His office did not immediately respond to a request for comment about Rull’s remarks.

Rull would face an uphill battle, according to Peter Ubertaccio, a political science professor and dean of the Stonehill College School of Arts & Sciences.

“Though primary challenges are becoming more frequent, it is still difficult to unseat an incumbent member of Congress,” Ubertaccio told WPRI 12 in an email. “Keating is always viewed as one of the most vulnerable members of Congress because it’s a fairly conservative district and he’s never over-performed with fundraising. But he has just as always been safely re-elected.”

Ubertaccio added, “He’s not out of step with 9th District Democrats on the issue of gun control and gun safety so it is hard to see how those issues could be used to defeat him in a primary election.”

Ted Nesi (tnesi@wpri.com) is WPRI 12’s politics and business editor and a Target 12 investigative reporter. He is a weekly panelist on Newsmakers and hosts Executive Suite. Follow him on Twitter and Facebook