The movement of Democratic superdelegates to presidential hopeful Barack Obama gained steam Friday, with endorsements expected from two more congressmen. Obama spokesman Dan Pfeiffer said the Illinois senator plans to receive the endorsement of Rep. Peter DeFazio of Oregon an event Friday in his homestate. Oregon holds it's primary on May 20. While polling in the Oregon has been sparse, Obama is believed to hold a significant advantage over New York Sen. Hillary Rodham Clinton. With DeFazio, he will have the endorsement of three of the state's four Democratic House members. Reps. Earl Blumenauer and David Wu earlier endorsed Obama, while Gov. Ted Kulongoski and Rep. Darlene Hooley have endorsed Clinton. ...