WASHINGTON — Returning to a central issue of the 2018 campaign, House Democrats on Thursday passed legislation to reverse Trump administration rules that allow expansion of health care plans that do not have to comply with the Affordable Care Act’s mandated coverage of pre-existing medical conditions.

The vote — 230 to 183 — was a jab at President Trump, who has pressed for ways around the coverage mandates of President Barack Obama’s signature domestic achievement while claiming he is committed to protecting Americans with chronic illnesses.

But it served a larger political purpose, kicking off a push by House Democrats on health care, an issue they see as central to winning back the White House and holding their gains in the House in 2020. Over the next two weeks, Democrats expect to pass a raft of legislation to drum home the point that, even as they clash with the White House over the findings of the Mueller report, they will continue to focus on proposals that help real people.

The House bill would roll back an October 2018 regulation by the Treasury Department and the Department of Health and Human Services that expanded the eligibility of states to receive waivers to the Affordable Care Act to “increase coverage options” — particularly with insurance plans that offer more limited coverage than those compliant with coverage mandates under the 2010 health law.