WASHINGTON — House Republicans scored a pre-dawn triumph today in their effort to scuttle former President Barack Obama’s health care overhaul, but it masked deeper problems as hospitals, doctors and consumer groups mounted intensifying opposition to the GOP health care drive.

After nearly 18 hours of debate and over two dozen party-line votes, Republicans pushed legislation through the Ways and Means Committee abolishing the tax penalty Obama’s statute imposes on people who don’t purchase insurance and reshaping how millions of Americans buy medical care.

It was a victory of high symbolism because Obama’s so-called individual mandate is perhaps the part of the statute that Republicans most detest.

Even so, the White House and Republican leaders confront a GOP and outside groups badly divided over the party’s high-stakes overhaul crusade.

The American Medical Association, the American Hospital Association and AARP, the nation’s largest advocacy group for older people, were arrayed against the measure. Seven years ago their backing was instrumental in enacting Obama’s health care statute, which President Donald Trump and Republicans are intent on erasing.

The hospitals — major employers in many districts — wrote lawmakers complaining about the bill’s cuts in Medicaid and other programs and said more uninsured Americans seem likely, adding, “We ask Congress to protect our patients.” Groups representing public, children’s, Catholic and other hospitals also expressed opposition.

America’s Health Insurance Plans, representing insurers, praised the legislation’s elimination of health industry taxes but warned that proposed Medicaid changes “could result in unnecessary disruptions in the coverage and care beneficiaries depend on.”

The legislation would defang Obama’s requirement that everyone buy insurance by repealing the tax fines imposed on those who don’t. That penalty has been a stick aimed at pressing healthy people to buy policies. The bill would replace income-based subsidies Obama provided with tax credits based more on age, and insurers would charge higher premiums for customers who drop coverage for more than two months.

“That’s what this whole bill was about, kicking people who weren’t politically popular,” Ways and Means Chairman Kevin Brady, R-Texas, said of Obama’s overhaul.

Ways and Means members worked until nearly 4:30 a.m. before approving the final batch of tax provisions in a party-line, 23-16, vote. The Energy and Commerce Committee panel continued working this morning, tackling a reshaping of Medicaid.

Conservative lawmakers and allied outside groups claimed the bill took too timid a whack at Obama’s law. Numerous GOP centrists and governors were antagonistic, worried their states could lose Medicaid payments and face higher costs for hospitals having to treat growing numbers of uninsured people.

House Speaker Paul Ryan, R-Wis., told reporters: “This is what good, conservative health care reform looks like. It is bold and it is long overdue, and it is us fulfilling our promises.” The last was a nod to campaign pledges by Trump and many GOP congressional candidates.

Ramping up pressure on GOP dissidents, a political group close to House Republican leaders said it is launching a TV ad campaign targeting 30 conservative lawmakers, mostly members of the hard line conservative House Freedom Caucus.