Sean Casten will take the Illinois Congressional District 6 seat after beating out incumbent Peter Roskam in Tuesday's election.
Roskam, R-Wheaton faced Casten, D-Downers Grove, in the midterm race. The district stretches from Crystal Lake to Darien and covers portions of DuPage, Lake, Kane, McHenry and Cook counties.
Roskam served in the office for six terms, since 2006. Roskam also served as the House Ways & Means Health Subcommittee Chairman and sat on the Tax Policy sub-committee.
Recently he has been vocal in his support for the controversial Tax Cuts and Job Act plan.
The highly competitive race has sparked national interest, as Roskam held one of the 23 seats Democrats hoped to flip in November with a so-called blue wave and retake the U.S. House of Representatives.
The seat in the district has been in GOP hands for four decades.
Casten, a former CEO and entrepreneur, has voiced strong opinions on the need to address climate change and implement health care and gun control reform.
"I didn’t run for office because I wanted to win an election – I ran for office because I wanted to legislate. The real work starts now," Casten said. "And while we all need to exhale, it is imperative that we keep this energy and love in place going forward. The grassroots led this effort, and leaders don’t quit until the work is done."
Casten won with 149,059 votes across the district compared to his opponent's vote total of 133,136, according to unofficial election result tallies by McHenry, DuPage, Kane, Cook and Lake counties.
All counties with the exception of Lake County favored Casten, unofficial results show.
McHenry County voters gave 52.4 percent of its vote to Casten with 26,529 people who voted, according to unofficial election results. Casten took 54.19 percent of the vote in DuPage County.
Roskam took Lake County with 56.03 percent of the vote, or 8,841 votes. Casten trailed behind with 43.97 percent of the vote, a total of 6,938 votes, according to unofficial totals.
Early voting, vote by mail, provisional and late arriving vote by mail ballots were not included in all totals reported.
In Cook County, Casten took 53.1 percent of the vote, and in Kane County he took just over 50 percent, unofficial totals show.