04/10/2010 05:12 am ET Updated May 25, 2011

What's Next For Murtha's Congressional Seat?

After the death of Rep. John Murtha (D-Pa.) on Monday, what happens to Pennsylvania's 12th district congressional seat?

Murtha died Monday at the age of 77 after complications from earlier gall bladder surgery. Just last week he became the longest-serving member of Congress in Pennsylvania history.

Now voters in Pennsylvania will most likely go to the polls to elect a replacement for the late congressman on May 18, according to the Washington Post's Chris Cillizza:

According to state law, the governor has ten days once the vacancy is officially declared to decide on the date for the special election, which can come no sooner than 60 days following that proclamation.

That likely means the special election will be held on May 18, which is the date already set for federal primaries around the state.

RealClearPolitics looks at the voting patterns of the 12th district, and at the results of previous election cycles:

Murtha's passing will set the stage for the seventh House special election in the 111th Congress, in a district that was evenly split in 2008 between John McCain and Barack Obama.
This year, Murtha was facing a primary challenge from Ryan Bucchianeri, a former Naval officer and placekicker on the Navy college football team. Republican Bill Russell, whom Murtha defeated with 58% in 2008, is running again, as is Republican businessman Tim Burns.
The area that now makes up the 12th District was heavily Republican from the Civil War to the 1930s, according to the Almanac of American Politics. Without Murtha, it is the quintessential swing district. McCain won it by fewer than 1,000 votes; John Kerry won it by 8,000 votes four years earlier.

Democrats have won every special election in this Congress, including one pick-up from the GOP in New York 23. Another is set in the Florida 19th on April 13, with yet another seat opening soon when Rep. Neil Abercrombie (D-HI) steps down to run for governor.

The Washington Examiner's Michael Barone has more details on political makeup of the area Murtha represented:

The 12th district was created in its present form as part of a Republican gerrymander in 2002. Traditional Republican territory was placed in the adjacent suburban Pittsburgh 18th district, which elected Republican Tim Murphy that year and has reelected him ever since. Republicans have fared less well in other Pennsylvania districts; they won a 12-7 edge in the delegation in 2002, but by 2008 Democrats reversed that and until Murtha's death had a 12-7 edge of their own. Murtha has been attacked for earmarking projects to his district and to companies headed by former aides and had spirited opposition in 2008 but won 58%-42%.