DeFazio initially had been expected to take an easy victory, but Robinson made a late surge in the district, which includes parts of western and southwestern Oregon.
DeFazio has blamed the viability of Robinson's campaign on a New York hedge fund executive, Robert Mercer, who contributed at least $178,000 to Robinson's campaign. DeFazio says Mercer opposes his attempts to institute Wall Street reforms.
The money allowed the Republican challenger to run radio and television commercials against DeFazio late in the campaign.
(Copyright 2010 by The Associated Press. All Rights Reserved.)