Republicans may seek to repeal the Affordable Care Act requirement that most Americans must have insurance coverage or pay a fine as part of their tax-overhaul package, part of a final push to undo or delay parts of the health law by the end of the year.

President Donald Trump, in posts on his Twitter account Wednesday, threw his support behind the proposal. “Wouldn’t it be great to Repeal the very unfair and unpopular Individual Mandate in ObamaCare and use those savings for further tax cuts…for the Middle Class. The House and Senate should consider ASAP as the process of final approval moves along. Push Biggest Tax Cuts EVER,” Mr. Trump wrote.

Republican leaders in both chambers have been wary of letting the political dynamics surrounding health care interfere with passing a rewrite of the tax code, but the president’s comments revived serious consideration of including a repeal of the individual mandate as part of the House GOP tax bill.

The idea of including the repeal, which is widely popular among Republicans, was back in play Wednesday, according to House GOP aides…