Illinois Representative Dan Lipinski lost the Democratic primary to a liberal challenger on Tuesday.

The eight-term Lipinski was known for his staunch opposition to abortion and votes against same-sex marriage, positions out of step with the Democratic Party. He also voted against the Affordable Care Act (ACA), former President Barack Obama's signature health care law.

With nearly all precincts reporting, businesswoman Marie Newman is leading Lipinski 47 to 45 percent, the AP reported. Lipinski conceded the race during a news conference.

Newman narrowly lost to Lipinski in 2018.

The ongoing coronavirus (COVID-19) epidemic might have contributed to Lipinski's loss as older voters who were more inclined to vote for the incumbent stayed home out of fears of contracting the virus.

During his time in Congress, Lipinski voted in favor of the Defense of Marriage Act (DOMA), which prohibited the federal government from recognizing the legal marriages of gay and lesbian couples, and supported the First Amendment Defense Act (FADA), a bill which sought to bar federal “discriminatory action” against those who oppose same-sex marriage based on a “religious belief or moral conviction.”

In 2015, the U.S. Supreme Court in Obergefell struck down state laws and constitutional amendments prohibiting same-sex marriage.

Lipinski remains opposed to marriage equality but says that he supports the high court's ruling “because it has been declared the law of the land.”

In 2010, Lipinski voted in favor of repealing “Don't Ask, Don't Tell,” the military policy which prohibited gay and lesbian troops from serving openly in the military.

According to, Lipinski voted 25.2 percent of the time with President Donald Trump's position even though a majority of voters in his district (55%) voted for former Secretary of State Hillary Clinton in 2016.