Map quest; District boundaries adjust to new population trends.

Byline: John J. Monahan

BOSTON - Proposed new state legislative district maps unveiled yesterday would double the number of minority-majority districts to 20, including the creation of one in the 15th Worcester District now represented by Democratic state Rep. Vincent A. Pedone.

They are among many changes to the boundaries of 160 House and 40 Senate districts, recommended by a Joint Redistricting Committee that realigned the districts to reflect changes in population over the last decade, including a population increase of almost 48,000 in Worcester County.

A majority-minority district is a congressional district in which the majority of constituents are racial or ethnic minorities. Whether a district is minority-majority is usually decided by U.S. Census data.

The proposal must be approved by the House and Senate and signed by Gov. Deval Patrick in time for the 2012 elections.

While the committee recommendations do not force any Worcester County incumbents to run against each other to remain in their seats - as they do in Lawrence and in one Western Massachusetts district - almost one in 10 state residents will find themselves in a new Senate district.

For example, the Senate district now represented by Sen. Stephen M. Brewer, D-Barre, would be moved to the east, losing the towns of Warwick, Royalston and Orange and gaining Ashby and Paxton. Warwick, Royalston and Orange would be shifted to the district now represented by Sen. Stanley C. Rosenberg, D-Northampton.

The district represented by Sen. Richard T. Moore, D-Uxbridge, had too many people and reworked district boundaries call for his district to give up two precincts in Northbridge.

State legislators and potential challengers began combing through the proposed new redistricting maps posted on the state Legislature's website yesterday afternoon with most of them getting their first definitive look at the proposed new boundaries. The maps are being rolled out now because state law requires anyone running for a House or Senate seat to live in the district for at least one year. The maps will be the subject of a public hearing before the joint committee next Tuesday and could be revised before going to the House and Senate for formal consideration the week of Oct. 31.

Like any law the redistricting maps must be approved in the House and Senate and sent to the governor for his signature. They are intended for use in the November 2012 state elections.

House Committee Chairman Michael...