Daniel William Lipinski (born July 15, 1966) is an American politician and political scientist who served eight terms as the U.S. representative for Illinois's 3rd congressional district from 2005 to 2021. A member of the Blue Dog Coalition, Lipinski was one of the most socially conservative Democrats in Congress.A conservative, Lipinski did not endorse President Barack Obama in the 2012 United States presidential election. Lipinski opposed legalized abortion and embryonic stem cell research and was one of 39 House Democrats to vote against the Affordable Care Act. He served a district whose Democratic Party electorate became increasingly liberal during his time in Congress, leading to his defeat in the Democratic primary for the 2020 election by Marie Newman.