Updated: 6:47 p.m.

The Massachusetts Legislature released its draft Congressional redistricting map today, drawing the homes of five-term Rep. Stephen Lynch (D) and freshman Rep. Bill Keating (D) into the same district.

Keating, whose primary residence is in Quincy, represents the current 10th district, which includes Cape Cod, where he has a longtime summer home. Under the new lines, Quincy would fall in the new 8th district, which includes most of Lynch’s territory.

A Massachusetts Democratic insider said that Keating will likely establish his summer home in Bourne as his primary residence, allowing him to run as a resident in the new 9th district, which includes the Cape and the South Coast region.

If he chooses to take on Lynch in a primary in the new 8th, Keating would face an uphill battle, but he would run with the advantage of incumbency in the new 9th.

In a statement, Lynch said he was pleased with the new district.

The Bay State lost a district in the decennial reapportionment process, so only nine Members will represent the commonwealth in the House beginning in 2013. Longtime Rep. John Olver (D) announced his retirement last month, allowing each incumbent running for re-election to have his own district.

Under the draft map, the district that includes the home of Rep. Richard Neal (D) retains the city of Springfield and its environs, which he currently represents. But it now stretches to include all of western Massachusetts, which is currently represented by Olver. That sets up a primary between Neal and former state Sen. Andrea Nuciforo Jr. (D) in the 1st district.

Nuciforo had $155,000 in the bank at the end of September while Neal had a comfortable $2.3 million campaign war chest.

Rep. Jim McGovern (D), who currently represents a district that snakes from the city of Worcester in the central part of the state all the way to the southern city of Fall River, would pick up a chunk of new territory under the new lines. The redrawn and renumbered 2nd district would no longer include some southwestern towns but would include Worcester and most of central Massachusetts, including the Democratic bastion of Amherst and Northampton. Eighty-seven percent of voters in Amherst voted for Barack Obama in the 2008 presidential election. All in all, it’s a very good new district for McGovern.

The district represented by Rep. John Tierney (D), which covers northeastern Massachusetts, remains essentially the same, adding a few towns to keep up with equal population requirements. State political operatives see Tierney as the most vulnerable of the delegation, but this map doesn’t appear to add to his vulnerability. His wife was convicted last year on federal tax charges, and the Boston Globe reported in late October that she would testify at the trial of her brother, who faces federal racketeering charges. The Congressman hasn’t been implicated in any illegal activity, but it’s hard to see how further trials won’t tarnish him.

Former state Sen. Richard Tisei, who was the GOP nominee for lieutenant governor in 2010, is said to be considering a bid for the seat and would be a competitive candidate. Lawyer Bill Hudak (R), who lost to Tierney in the previous cycle, may challenge him again.

Democratic Rep. Mike Capuano’s current district, anchored in portions of Boston, Cambridge and Somerville, is similar to the redrawn 8th district. But the new 8th becomes a solid majority-minority district by adding portions of the towns of Milton and all of the town of Randolph. Fifty-six percent of residents in the newly drawn 8th are minorities, according to the state Legislature.

Democratic Rep. Niki Tsongas’ district is shored up under the new draft map. There were earlier rumors that she might be vulnerable under the new lines, but that proved not to be the case.

“There’s a clear loser here: Elbridge Gerry,” quipped longtime Bay State Democratic strategist Scott Ferson, referring to the historical father and namesake of gerrymandering. “By Massachusetts standards … I gotta give the redistricting team credit,” he said, praising the fact that the map keeps communities of interest together.

The lack of obvious gerrymandering doesn’t mean any of the Members are particularly vulnerable.

“For incumbent protection, it’s a pretty sweet map,” Ferson said.

The chairmen of the Special Joint Committee on Redistricting, which released the maps, asked for public comment in a press release. They said they would evaluate public feedback on the draft map over the next three days, before submitting a recommendation to the full Legislature.