Independent Steven Porter has long been a vocal critic of incumbent Rep. Phil English – and gave him more than a cursory challenge for Pennsylvania’s third-district seat in 2006.

Now, as English faces perhaps his biggest challenge from Democrat Kathy Dahlkemper, Porter could end up being English’s best friend.

The Wall Street Journal notes that Porter is getting the endorsement from the liberal political action committee Blue America:

In northwestern Pennsylvania, where two-time Democratic challenger Steven Porter has launched an independent progressive bid against Republican Rep. Phil English, Blue America has endorsed Mr. Porter rather than the Democratic nominee, Kathy Dahlkemper.[Activist Howie] Klein has praised the third-party run and helped Mr. Porter raise money despite Democratic concerns that a divided liberal vote will hurt the odds of a party pickup in a tight race.

Porter, without much backing from the Democratic party, took 42 percent of the vote in 2006.

Dahlkemper is getting considerable support from the party this year — but she could see Porter cut into her possible vote haul in November, a la Ralph Nader in 2000.