The new congressional map, drawn and passed by the Democratic-controlled Maryland General Assembly, was signed into law by Governor Martin O'Malley on October 20, 2011.

The map made the 6th district, at that time represented by Republican Roscoe Bartlett, much more favorable to Democrats.

[3] After Rosen won the primary, she was forced to withdraw from the race on September 10, 2012, after evidence surfaced that she had voted in both Maryland and Florida in the 2006 and 2008 elections.

However, her Florida voting registration reportedly also gave her access to state and federal elections there, something which was not allowed by Maryland law.

The redrawn 4th district includes parts of Anne Arundel and Prince George's counties.

Representatives State officials Facing a district that had been significantly redrawn to favor the Democrats (going from a seat that McCain carried with 57%, Obama would have carried the redrawn seat with 56%), the Bartlett campaign faced further difficulties when the Federal Election Commission fined Bartlett $5,000 for repeatedly failing to submit accurate campaign finance disclosure reports.

However, it was later revealed that in 2001 Bartlett had supported a constitutional amendment which did not include the rape and incest exceptions.