CHICAGO (CBS) — Democratic challenger for the 6th Congressional District Sean Casten has defeated Republican incumbent Peter Roskam.

With 77 percent of precincts reporting, Casten led Roskam with 53 percent of the vote. Roskam had 47 percent.

The race was considered a dead heat with political newcomer, Democrat Sean Casten, edging incumbent Republican incumbent Peter Roskam throughout the final weeks of the campaign.

Roskam, from Wheaton, is currently in his sixth term as a U.S. Congressman. He is a member of the House Ways & Means Committee. He also sits on the Tax Policy Subcommittee. Roskam also served in the Illinois House and Senate.

RELATED: Complete Illinois Election Results 

Casten is a political newcomer. He’s from Downers Grove and works as a scientist and a businessman who founded Recycled Energy Development LLC, a clean energy company. He has criticized the Trump administration on its dismissal of climate change and related issues.

Casten has positioned himself as the opposite of Roskam, who he said has sided with President Trump more than 90 percent of the time with legislation.

During debates for the Chicago Tribune and WTTW, the candidates said they agreed on a few positions, including a ban on bump stocks and high capacity magazines. They disagreed on a ban on assault weapons. Roskam said it wasn’t necessary. Casten said there should be a ban.

When asked if a pharmacist should refuse to fill a prescription based on their religious beliefs, Casten said no but Roskam said yes.

The 6th District of Illinois covers parts of northern Cook County with a population of more than 700,000. It also goes into DuPage, Kane and Lake counties.

Suburbs include Algonquin, Barrington, St. Charles, Lake Zurich, Wheaton, Downers Grove, Glen Ellyn, South Elgin, Lake in the Hills, Lake Barrington and Palatine.

The Casten-Roskam race was considered one of the most expensive races in Illinois.

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Candidate Q & A: 6th Congressional District Republican Incumbent Peter Roskam

Roskam: “There’s no question they’ve benefited. They’ve benefited a billion dollars in tax relief to the sixth district alone. PolitiFact evaluated Sean Casten’s claims and they said what he was saying is false, he’s creating an impression that’s false. That people are paying more in taxes. They even said he didn’t get his basic math right.”

Candidate Q & A: 6th Congressional District Democratic Challenger Sean Casten

Casten: “He voted 62 times to repeal the ACA. Prior to the ACA, there were no protections for people with preexisting conditions. He voted to repeal preexisitng conditions 62 times. They framed this is as repeal and replace but never once introduced a replacement bill.”