WASHINGTON — Weeks before the midterm elections, a Democratic super PAC is jumping into the two biggest Chicago-area House races, bankrolling TV spots against GOP incumbents Peter Roskam and Randy Hultgren that started airing Wednesday.

The House Majority PAC is making the independent expenditures in hopes of flipping the 6th and the 14th Congressional districts, which are key to the Democrats’ bid to win control of the U.S. House of Representatives in November.

A spokesman for The House Majority PAC, Hannah Blatt, said the group is spending $1.9 million against Roskam and $887,000 to defeat Hultgren through television ads that take aim at their records on taxes and health care.

That’s on top of about $120,000 the House Majority PAC spent in direct mail in September opposing Roskam.

This is the biggest infusion of outside money to date in these districts, which are anchored in the western Chicago suburbs.

The Democratic nominees, Sean Casten in the 6th and Lauren Underwood in the 14th, are both first-time candidates.

Since Casten and Underwood are political newcomers, the House Majority spots have the freedom to also accuse Roskam and Hultgren for being out of touch because of their years in Washington. Roskam was first elected in 2006; Hultgren in 2010.

The Democrats are stepping up in Roskam’s district in the wake of a Republican super PAC, the Congressional Leadership Fund, spending $731,003 to date to oppose Casten, according to the Federal Election Commission.

Most of the Congressional Leadership Fund cash was for a media buy in August. Including earlier spending, the GOP group plans an outlay of $2.4 million to defend Roskam.

The New Prosperity Foundation, based in Chicago, in September told the FEC it spent $75,000 in digital ads to oppose Casten and $50,000 to back Roskam.

The House Majority ads will run through election day.

The Democratic independent expenditure comes as early voting has started in Illinois.

Third-quarter fundraising totals will be released by the FEC in mid-October. On Wednesday, Casten’s campaign said he raised $2.6 million, compared to Roskam’s campaign haul of $1.3 million.

On Wednesday, Casten was bolstered by leaders of several Democratic-allied groups — the Human Rights Campaign; NARAL; the Sierra Club Illinois Chapter and labor unions — at a press event.

On Tuesday, the Casten campaign started running an ad linking Roskam to Trump.