WASHINGTON — Ever since Republicans got down to the business of repealing the Affordable Care Act, the Senate has been singled out as the likely problem. Any plan that could zoom through the House would hit roadblocks among Senate Republicans, many of whom have resisted a wholesale repeal of the health law without a robust replacement plan.

But after weeks of loud protests, boisterous town hall meetings and scores of quieter meetings between members of Congress and health care professionals, patients, caregivers and hospital managers in their districts, it is becoming increasingly likely that a consensus in the House will be just as hard to reach.

The most conservative House members are pushing for a fast repeal of the health law with only a bare-bones replacement to follow: possibly just bigger incentives for people to open health savings accounts to fund their own health needs. Other Republicans are more interested in taking their time to come up with a replacement plan that, as of now, they have failed to cobble together beyond a menu of options.

Among the increasingly concerned lawmakers are those who represent the 24 Republican congressional districts that Hillary Clinton won in the presidential election — roughly the edge Republicans hold over Democrats in the House — and another dozen in districts that President Barack Obama took in 2012 but President Trump won in November. If 25 conservative hard-liners oppose any robust replacement plan, and 30 swing-district House members demand a more generous plan, passage of a compromise bill will be in jeopardy.