WASHINGTON — Republicans are united on repealing President Barack Obama’s health care law, but ideologically and practically speaking, they’re in different camps over replacing it. Getting the factions together won’t be easy.

Some Republicans would revise and rebrand “ObamaCare,” junking unpopular provisions like its requirement that most Americans carry health insurance, while preserving well-liked parts. Others would rip up the Affordable Care Act, or ACA, and not replace it.

President-elect Donald Trump and Republican congressional leaders will have to unite the groups on complicated changes affecting the financial and physical well-being of millions of people. For some constituents in fragile health, it’s literally a life-and-death debate.

Republicans have “a really narrow path,” says Grace-Marie Turner of the Galen Institute, a free-market health care research organization. “They’ve got to deal with the politics of this, they’ve got to make sure they come up with good policy, and they also have process challenges.”

Success is not guaranteed, and Republicans may come to regret that their party defined itself as totally opposed to “ObamaCare.”

Yet House Ways and Means Chairman Kevin Brady seems unfazed by the challenge. “It’s like tax reform,” says Brady, R-Texas, explaining that many pieces will be pulled together. “Unlike ObamaCare, which ripped up the individual market, this will be done deliberately, in an appropriate timetable.”

Republicans say they will move quickly to repeal the ACA, while suspending the effective date to allow them to craft a replacement. Here’s a look at the GOP camps and who’s in them:

Revise & rebrand

Many Republicans may quietly be in this contingent, but fear being accused of promoting “ObamaCare-lite.”

They’d strip out some of the ACA’s taxes and requirements. The unpopular “individual mandate” to carry health insurance or risk fines could be replaced with other persuasion short of a government dictate. Rules on insurers would be loosened.

But popular provisions such as protecting those with pre-existing health conditions would be retained in some form, as well as financial assistance for low- and moderate-income people. The requirement that health plans cover adult children until age 26 would be fairly easy to preserve, since employers have accommodated it.

A rebranded version of Obama’s law may well cover fewer people. But its GOP advocates believe most Americans will find their goal of “universal access” politically acceptable when measured against the Democratic ideal of “universal coverage” underwritten by government.

Many GOP allies in the business community favor revising the ACA. That includes major players among hospitals, insurers and pharmaceuticals.

Trump may have given this group some cover by saying that he wants to keep parts of the law.

Budget hawks

For budget hawks, unwinding the Obama health law is a beginning. Next they could move on to much bigger objectives like restructuring Medicaid and Medicare, and placing a cost-conscious limit on tax breaks for employer coverage.

Budget hawks see health care as the main driver of government deficits, and they are loath to address that imbalance by raising taxes. Instead they want to rewrite the social compact so individuals accept more responsibility and risk for their health care.

House Speaker Paul Ryan is the most prominent member of this camp, and his “Better Way” agenda is its road map. Georgia Rep. Tom Price, Trump’s nominee for Health and Human Services, is a budget hawk. Vice President-elect Mike Pence has been in the same orbit throughout his career.

The problem for budget hawks is that the 2016 political campaign did not give them a mandate. Issues like Medicare and Medicaid were scarcely discussed. Trump said he wouldn’t cut Medicare, and sent conflicting signals on Medicaid.

Many Democrats can’t wait for Republicans to follow the call of the budget hawks. Betting that will backfire, House Democratic Leader Nancy Pelosi is rallying her lawmakers against “attacks on the ACA and Medicare.”

The rip-it-up society

The most conservative lawmakers want to “pull ObamaCare up by the roots as if it never existed,” says Republican political consultant Frank Luntz. That sentiment is embodied by the 40 or so members of the House Freedom Caucus, and it’s probably broadly shared among conservatives.

Some do not believe the federal government should be involved in health care, and they couldn’t care less about replacing the ACA.

GOP leaders may need these lawmakers to advance on replacement legislation; coaxing them to a middle ground might not be possible.