Congressional Quarterly has released an analysis of the 2010 midterm Congressional elections, listing 100 competitive districts across the country, including eight toss-ups in Pennsylvania.

From the CQ analysis:

With 257 of the 435 U.S. House seats, Democrats are strongly favored to retain their majority in the 2010 elections -- though history points to party losses in the first midterm election of President Obama.

Most of the 435 congressional districts have such well-entrenched incumbents that the 2010 House races there will be landslides. But CQ Politics has preliminarily identified 100 districts, 59 of which are held by Democrats, where the contests should be highly or mildly competitive. Of these, CQ Politics rates three districts, all now held by Republicans, as leaning toward takeover by the challenging party: Louisiana 2nd Dist., Pennsylvania 6th Dist. and Illinois 10th Dist.

The Pennsylvania districts that CQ Politics lists as competitive are the 6th (held by Republican Jim Gerlach, who is not seeking re-election); the 12th (held by Democrat John Murtha); the 7th (held by Democrat Joe Sestak, who probably will not seek re-election); the 3rd (held by freshman Democrat Kathy Dahlkemper); the 4th (held by Democrat Jason Altmire); the 10th (held by Democrat Chris Carney; the 11th (held by Democrat Paul Kanjorski); and the 15th (held by Republican Charlie Dent).

While CQ Politics lists Dahlkemper, Altmire, Carney, Kanjorski and Murtha in the "favored to win" re-election column, it still sees the races as competitive. Same for Dent, who is "favored to win" in the 15th.

Pennsylvania's other 11 Congressional districts are listed in the "safe Democratic" or "safe Republican" columns.

Here's my take on the CQ analysis. The 6th District will go to the Democrats, but the 7th District should return to Republican control. Republicans have a good chance of unseating Dahlkemper, Carney, Kanjorski and Murtha. I don't see Altmire or Dent losing their seats.

The key to a Republican comeback in 2010 is how badly Barack Obama continues to stumble. If the economy is still in shambles, if U.S. foreign policy is still in disarray, if Obama continues to march the country toward socialism, expect huge GOP gains in Congress.

The 2010 Congressional elections will be a referendum on Obama. If "change" doesn't come real fast, look for voters to toss out career politicians like Murtha and Kanjorski to send a message to Obama.

To review other House races, visit CQ Politics online for an interactive map.