National Democrats are characterizing the special election for the late Rep. John Murtha's (D) Pennsylvania seat as a must-win for the GOP. The Democratic Congressional Campaign Committee sent out a release Monday noting the 12th district "is the only district in the country that Senator Kerry won and President Obama lost. … [It is] exactly the type of district that House Republicans need to win this cycle."

Meanwhile, the candidates have very different closing messages.  

Democrat Mark Critz, who was joined by Sen. Bob Casey Jr. (D-Pa.) for several campaign stops Monday, continued to talk about jobs and the economy.
"I've laid out a jobs plan that will get folks back to work," Critz said in Washington, Pa. "Bringing economic development to western Pennsylvania will be my top priority."

Meanwhile, Republican Tim Burns directed his fire toward President Barack Obama and House Speaker Nancy Pelosi (Calif.).

"This election is literally a referendum on the Obama-Pelosi agenda," Burns said at an event in Richland. "We are going to send a loud message to Washington that the American people are not going to stand for them not listening. We are going to take back this government."