There's been a lot of talk that many key races this year will be fought in the frost belt, with New York, Pennsylvania, and Ohio having more than any state. One area that is a microcosm of that is the Philadelphia metropolitan area. While the two Philadelphia House seats have never been in play, many others are:
Pennsylvania - This is the key area for this race. Sestak will get Philadelphia, Pittsburgh, and some smaller urban areas throughout the state. Toomey will get the rural areas and likely grab the Reagan Democrats in western Pennsylvania. The Philadelphia suburbs used to be Republican, but the area has changed. The counties around the city voted for Obama by 10-20 points. Joe Sestak's district is here. Sestak would need a big turn-out in this area and to hold on to their votes. It looks like Toomey may hold his own here. Toomey has a nice, but not solid lead, according to the polls. This should be the 4th Republican pick-up after North Dakota, Arkansas, and Indiana. A solid win here would mean bigger gains are possible. A struggle here likely would mean Wisconsin, Colorado, and other possibilities are in trouble.
Delaware - Some people, including me, think this race won't be competitive. That's not what makes it interesting. Christine O'Donnell is a huge symbol of the tea party. Whatever showing she gets will largely be due to tea partyers. This'll be a sign of what they can accomplish.
Pennsylvania 7 - This is Sestak's open seat and one that looks to be a sure pick-up for the GOP. They have a strong candidate who has done well fundraising. Before Sestak, Republican Curt Weldon held the seat for 20 years. This is a D +3 district. While Republicans expect to pick up many Republican seats, this will show they can pick-up Democratic seats.
Pennsylvania 8 - Similar to the 7th, but this has incumbent Patrick Murphy. Like Sestak he took the seat from a Republican in 2006. This is a D +2 district. Mike Fitzpatrick is ahead in the polls. This exemplifies Republicans beating incumbents.
Pennsylvania 6 - Obama did better in this district than he did in the 7th or 8th, but Republican Jim Gerlach held on by 1 and 4 points the last two elections. Gerlach should hold the seat fairly easily in this environment, but it's the type the GOP could lose if the tide isn't strong enough.
Pennsylvania 13 - This used to a swing district but the 2002 redistricting turned it solidly Democratic with Obama taking 59% of the vote. Allyson Schwartz's seat is considered safe, but I drove around the district last night. I saw a lot more Adcock yard signs than Schwartz. We haven't seen polling here, but if the wave is big enough even this district could fall.
Delaware - Delaware is heavily Democratic and likely needs a Mike Castle type to pick off enough Democratic votes to win. The GOP has held this seat for the last 18 years and 34 of the last 44. It should be a loss. A win here would could mean the Republicans don't lose any of their own seats.
New Jersey 3 - Similar to the seats on the other side of the river, this suburban Philadelphia went to Obama, by a small margin, and was held by a Republican until the 2008 switch. Former Eagle Jon Runyan is running for the Republicans. In a strong GOP year, he should win just by being an ex-Eagle alone.
New Jersey 12 - A touch to the north in Princeton, Republicans haven't had this one in 12 years. Obama got 58% of the vote. Like Pennsylvania 13, this would mean ousting an entrenched incumbent.
New Jersey 2 - The southern portion of New Jersey. Frank Lo Biondo has held the seat longer than Jim Gerlach, but he's never won a race by less than 20. Obama won the district after pushed squeaked by. In a Democratic year this would be a target. As it is now, the seat isn't mentioned at all.