Oregon Rep. David Wu's former GOP challenger said there were signs of the Democrat's mental illness during their 2010 campaign.

Wu said on ABC's "Good Morning America" on Tuesday that he’s been seeking "both counseling and medication" since October, when the congressman's bizarre behavior caused his staff to suggest he seek hospitalization. 

"The only sign I had was that he basically hid for the last 60 days of the election," Rob Cornilles, a sports management consultant, told The Ballot Box.

Cornilles said that Wu agreed during the campaign they would have multiple debates, but subsequently reneged and would only participate in one.

"That, to me, was disturbing," he said.

Days before the Nov. 2 vote, Wu sent his staff a picture of him wearing a tiger Halloween costume and e-mails written in the voice of his children. His behavior prompted six of his 20 staffers to quit their jobs.

"I don't think that voters need to know everything about a candidate," said Cornilles. But anything to do with how a candidate would perform his official duties is relevant, he added. "Those are things voters have a right to know. And that's what a campaign is for — them to see you in that environment. He was pretty elusive during that time. I think that was pretty unfortunate."

Cornilles, who lost to Wu by 13 points in November, said it's not up to him whether the revelations about the Democrat's behavior will be an issue next year. "That's up to the voters if it will be an issue to them," the Republican said. "Anything that affects a candidate's judgment and ability to do their job is something people will be watching, as they should."

Cornilles continued: "I ran against David Wu because I thought he was an ineffective congressman. I think it's important to point out that I hope he gets well because we need an effective congressman in this district. I want him to be effective.

"And until he gets well I'm disappointed because we're not getting represented like we should be.”

Meanwhile, Oregon Republicans are excited about the possibility of a rematch between Cornilles and Wu. 

Rachel Lucas, the Washington County GOP chairwoman, said there's been "a lot of buzz" about Cornilles running again. "I personally would hope that he does and he's in a good position to do so," she said.

Cornilles said he's not sure whether he'll challenge Wu again in 2012.

"I won't deny that I'm getting a lot of encouragement," said Cornilles, although he noted the National Republican Congressional Committee has yet to contact him. "But my decision will be based on my family, certainly my business and also the way that the district is made up [after redistricting]. There's a lot of moving parts right now."