U.S. Rep. Sean Casten easily dispatched Mahnoor Ahmad of Oakbrook Terrace and Charles Hughes of Chicago in Tuesday’s Democratic primary in the largely suburban 6th District as he seeks a fourth term.

With 75% of the vote counted, Casten led with 77% of the vote over Ahmad, with 14%, and Hughes, with 9%, according to unofficial results.

The former owner of a clean energy business, Casten has made taking on climate change a pillar of his tenure in Washington. He’s also campaigned heavily on protecting reproductive rights.

Ahmad challenged Casten from the left. She supports a permanent cease-fire in the Israel-Hamas war, the Green New Deal and “Medicare for All.”

Hughes, from Chicago’s Garfield Ridge neighborhood near Midway Airport, was a precinct worker for former longtime U.S. Rep. Bill Lipinski. He finished third in the 2022 Democratic primary, trailing Casten and Newman with just over 3% of the vote.

Casten, who unseated six-term Republican Rep. Peter Roskam in 2018 to take over the seat once held by conservative icon Henry Hyde, bested freshman U.S. Rep. Marie Newman of La Grange in the Democratic primary two years ago in the state’s only incumbent-on-incumbent Democratic congressional primary.

In the 2022 general election, Casten defeated Orland Park Mayor Keith Pekau, a Republican who gained notoriety for challenging state COVID-19 mandates and aligned himself with the far-right group Awake Illinois.

The 6th District includes stretches from Lombard southeast to Tinley Park, taking in Chicago’s Beverly and Mount Greenwood neighborhoods and areas near Midway.

Casten will face Republican Niki Conforti of Glen Ellyn in the Nov. 5 general election.