A poll commissioned by Democrat Sean Casten’s congressional campaign finds the political newcomer ahead of U.S. Rep. Peter Roskam, R-Ill., with just four weeks to go before the November election.

It’s the second poll showing Casten with a slight lead, according to the Democrat’s congressional campaign. Casten’s campaign last month released a poll that found Casten ahead 47 to 44 percent. A poll released on Sunday by Casten’s campaign finds that lead stretched to 49 to 44 percent with 7 percent undecided, the latest poll conducted by the Garin-Hart-Yang Research Group found.

The poll was taken Sept. 29 through Oct. 1 of 400 likely general election voters in Illinois’ 6th Congressional District, which covers suburbs in Cook, Lake, Kane, McHenry and DuPage counties. The margin of error is plus or minus 4.9 percentage points.

Among women voters polled, Casten is up 15 points — 54 percent to 39 percent. For men voters polled, Roskam is up by 7 points — 50 percent to 43 percent, according to the poll. Casten is also performing better with voters age 18 to 39 — polling 58 percent to Roskam’s 25 percent.

The race between Roskam, who has held the seat since 2007, and Casten, a political newcomer and a former energy company executive, is under a microscope nationally as Democrats try to regain control of the chamber.

Roskam’s campaign said they’re aware the race is close but expressed optimism in the incumbent’s chances. The campaign on Sunday also sought to link Casten to Illinois House Speaker Mike Madigan, echoing TV ads which say “both would make us pay a lot more” in taxes.

“We are confident voters will stick with Peter Roskam, who has been an effective leader for Illinois and is rated as one of the most bipartisan members of Congress,” spokeswoman Veronica Vera said.

Meanwhile, Casten got a boost Sunday from a group backing him, the Jewish Democratic Council of America, whose ranks include prominent major Democratic donors.

The executive director of the group, Halie Soifer, visited a Casten campaign office in Barrington and then joined volunteers canvassing door to door.

A spokesman for the organization said Sunday the group will target Jewish voters in the district with paid ads in print and social media.

Contributing: Lynn Sweet