An adviser to Quincy Representative William R. Keating now says the congressman is unlikely to stay in his current district and face off against South Boston Representative Stephen F. Lynch.
Keating will instead move to Cape Cod — where he owns a summer house in Bourne — to run in a newly created district that will encompasses the Cape and the South Coast.
Prompting the move is a sweeping new plan, released today, for the state’s congressional districts. The proposal would have pitted the two Boston-area Democrats against one another, while creating the new seat in the southeastern part of the state.
The new map will also expand the state’s only majority minority district — now represented by Michael Capuano of Somerville — extending it from Somerville and Everett, through Boston, and down to minority precincts in Milton and Randolph.
Meanwhile, the two western Massachusetts districts have been completely revamped, with the Berkshires set to be represented by Richard Neal.
The two co-chairs of the joint redistricting committee acknowledged they have made major changes to the district boundaries that could prompt concerns among the nine Democratic incumbents in the state’s Washington delegation.
“Everybody needs to digest this,’’ said Senator Stanley C. Rosenberg of Amherst.
His House counterpart, Michael J. Moran of Brighton, strongly defended the overhaul, which was driven by the fact the state was forced to eliminate one seat because of lagging population growth in Massachusetts.
With veteran Representative John Olver of Amherst retiring, many expected the committee to simply merge his communities into surrounding districts to avoid crunching two incumbents.
But Moran said the creation of a South Coast and Cape Cod District was a priority for a part of the state that has long been carved up into three districts.
“We’ve drawn up what we believe ... is an accurate reflection of where the people of the Commonwealth are,” Moran said when he was asked why the Democrat-dominated committee did not try to avoid putting two Democratic incumbents together.
“This is clearly not drawn for incumbents,’’ he said. “If it was, it would look a little different.”
After a Globe story reported this weekend that Niki Tsongas, the delegation's only woman, was set to lose the City of Lawrence, a strong Democratic base in the Merrimack Valley, House leaders backed off that plan.
Representative James P. McGovern of Worcester, who now represents a district that winds from that city down to Fall River, will now see his district push west to Amherst and Northampton and north into Franklin County to the Vermont border.
Leaders of the House and Senate spent months working through the contentious issue of redistricting. The plan must now be approved by the full House and Senate before the Legislature’s session ends Nov. 16 and then signed by the governor.
In some regards, the redistricting process in Massachusetts is easier than it is in other states, because the overwhelmingly Democratic political leadership wants to retain the party’s advantage.
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