UPDATED 11/3/10 9:16 a.m.

GRAYSLAKE, Ill. (CBS) – In a surprising development, Tea Party-backed Republican Joe Walsh is on the cusp of defeating Democrat Melissa Bean in the northwest suburban 8th Congressional District.

LISTEN: Newsradio 780’s Regine Schlesinger Reports

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Walsh has declared victory, but the race has not been called officially. But with 99 percent of the precincts reporting, Walsh had 96,636 votes, or 49 percent, compared with 95,839 votes, or 48 percent, for Bean, and 6,412 votes for Green Party candidate Bill Scheurer.

Beut Bean campaign spokesman Jonathan Lipman says there could be thousands of votes left to be counted. Lipman says the campaign is working to understand just how many absentee and provisional ballots are still uncounted.

While Bean outpolled Walsh in the Cook County suburbs in the district, Walsh took 50 percent to Bean’s 47 percent in Lake County, and 52 percent to Bean’s 43 percent in McHenry County, Pioneer Press reported.

Walsh ran his campaign according to the so-called “28 founding principles” of the United States, “not the least of which are limited government, free enterprise and the rule of law as established by our Constitution.”

Government spending, gun rights, and curbing illegal immigration were among the major themes of his campaign.

In the last few weeks of the campaign, the Bean campaign began airing attack ads portraying Walsh as a right-wing extremist.

The ad campaign took Walsh to task for supporting concealed weapons, calling for the abolition of the U.S. Environmental Protection Agency, and calling for a ban on abortion without exception, including in cases of rape and incest.

Sound bites used in the ad showed Walsh saying, “We’re at the beginning of a war,” “This is a revolution,” and, without specifying what he is talking about, “Some people may say that’s reckless, but so what?”

“Reckless? Joe, that’s dangerous,” Walsh says in the ad.

Walsh took Bean to task for the ad in his own campaign video.

“Melissa Bean, you’ve got to be kidding me,” he said. “Ten percent unemployment, foreclosures up throughout our district, people’s entire savings wiped out, our economy is in tatters – and you attack me for my position on abortion?”

Walsh said voters in the 8th District were “just trying to keep their heads above water” and were “upset with (Bean’s) vote for a government takeover of our health care system.”

Bean won the seat in 2004, when she upset six-term Republican incumbent Phil Crane. She held the seat easily in subsequent elections in 2006 and 2008.

With Walsh’s anticipated victory, the GOP will hold 11 of Illinois’ 19 seats in the U.S. House of Representatives.

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