HARRISBURG - Republican lawmakers unveiled a proposed map Tuesday of Pennsylvania's 18 new congressional districts. It was swiftly criticized as an attempt to protect members of their own party.

The proposed new district for U.S. Rep. Pat Meehan (R., Pa.), in particular, was singled out for its zigzag shape, which Democrats alleged was drawn to excise Democratic areas in favor of more solidly Republican ones.

Meehan has been considered one of the more vulnerable House members in 2012, representing a district carried by Democratic presidential candidates John Kerry in 2004 and Barack Obama in 2008.

"I'm trying to think of the appropriate animal name, or monster name, for it," said State Sen. Andrew Dinniman (D., Chester) after peering at the proposed map for Meehan's Seventh District.

"It resembles roadkill," chimed in Bill Patton, a spokesman for Democrats in the House.

In a statement Tuesday, Meehan said: "I understand that the district needed to gain population and expand, and that is what the state legislature has done. I appreciate how hard it must have been to complete this redistricting process."

His proposed district would include parts of five counties - Delaware, Chester, Lancaster, Montgomery, and Berks.

Some heavily Democratic towns in Delaware County with sizable African American populations - Upper Darby among them - were snipped out and placed in U.S. Rep. Bob Brady's Philadelphia-centered First district.

Delaware County Democratic Chairman David Landau called the redrawn district a "Meehan-mander."

"It kind of looks like an oil spill," Landau said. "We now have Amish farmers crammed in with the inner-ring suburbs. What is this district now? What is the common interest? The only interest here is pure power."

Under the proposal, Montgomery County would be split among five districts: the Eighth, represented by Michael Fitzpatrick, a Republican; the Seventh, represented by Meehan; the Sixth, represented by Jim Gerlach, a Republican; the 13th, represented by Allyson Y. Schwartz, a Democrat; and the Second, represented by Chaka Fattah, a Democrat, who would pick up Lower Merion.

Under the proposed map, Gerlach's Sixth District would extend into Lebanon County; Easton would be separated from Allentown and Bethlehem in the Lehigh Valley; and the districts of U.S. Reps. Jason Altmire and Mark Critz, both Democrats, would be combined into a new 12th District in the western part of the state, forcing them to run against each other next year.

The redrawing of congressional maps is done every 10 years to reflect population changes. In next year's election, Pennsylvania's delegation will shrink by one seat.

This year, Republicans were in a position to redraw the boundaries because they control the governor's office and the legislature.

A Senate vote on the proposed map is scheduled for Wednesday, and Republicans hope to make the new map law soon.

Contact staff writer Angela Couloumbis at 717-787-5934, acouloumbis@phillynews.com, or @AngelasInk on Twitter.