Rep. David Wu's (D-Ore.) 2010 opponent will run for the seat Wu will soon vacate. Republican businessman Rob Cornilles, who held the scandal-tarred Wu to a 55 percent to 42 percent win last election, will announce his candidacy Thursday morning in Oregon.

Wu has not yet resigned from Congress despite saying that he would leave as soon as the debt-ceiling debate had ended. He decided to resign after Democratic House leaders pressured him to do so following reports that the lawmaker had a sexual encounter with the teenage daughter of a campaign donor last fall.

Cornilles will have an uphill battle in the election, although special elections can be low-turnout and quirky events that sometimes lead to surprise victors. The district gave President Obama 61 percent of its vote in 2008 and leans strongly Democratic. Wu's issues had started to surface during the election, when several of Wu’s staffers resigned because of reported “bizarre” behavior the lawmaker had been exhibiting, including sending his staff a photo of himself wearing a tiger costume and sending additional emails in the voice of his young daughter.

Many Democrats are already in the race. Brad Avakian, commissioner of the state Bureau of Labor and Industries, and state Rep. Brad Witt already had been running in the Democratic primary against Wu before he resigned. State Sen. Suzanne Bonamici will soon announce her candidacy and already has a campaign website up.

The special election date will be scheduled by Democratic Gov. John Kitzhaber once Wu steps down.