WASHINGTON — President Donald Trump is rallying support for the Republican health care overhaul by taking his case directly to GOP lawmakers at the Capitol, two days before the House plans a climactic vote that poses an important early test for his presidency. Top House Republicans unveiled revisions to their bill in hopes of nailing down support.

At a rally Monday night in Louisville, Kentucky, Trump underscored what he called “the crucial House vote.”

“This is our long-awaited chance to finally get rid of Obamacare,” he said of repealing former President Barack Obama’s landmark law, a GOP goal since its 2010 enactment. “We’re going to do it.”

Trump’s closed-door meeting with House Republicans was coming as party leaders released 43 pages worth of changes to a bill whose prospects remain dicey. Their proposals were largely aimed at addressing dissent that their measure would leave many older people with higher costs.

Included was an unusual approach: language paving the way for the Senate, if it chooses, to make the bill’s tax credit more generous for people age 50-64. Details in the documents released were initially unclear, but one GOP lawmaker and an aide said the plan sets aside $85 billion over 10 years for that purpose.

The leaders’ proposals would accelerate the repeal of tax increases Obama imposed on higher earners, the medical industry and others to this year instead of 2018. It would be easier for some people to deduct medical expenses from their taxes.

Older and disabled Medicaid beneficiaries would get larger benefits. But it would also curb future growth of the overall Medicaid program, which helps low earners afford medical coverage, and let states impose work requirements on some recipients. Additional states could not join the 31 that opted to expand Medicaid to more beneficiaries under Obama’s law, the Affordable Care Act.

In a bid to cement support from upstate New Yorkers, the revisions would also stop that state from passing on over $2 billion a year in Medicaid costs to counties. The change was pushed by Rep. Chris Collins, R-N.Y., one of Trump’s first congressional supporters. Local officials have complained the practice overburdens their budgets.

Republican support teetered last week when a nonpartisan congressional analysis projected the measure would strip 24 million people of coverage in a decade. The Congressional Budget Office also said the bill would cause huge out-of-pocket increases for many lower earners and people aged 50 to 64.

Democrats have opposed the GOP repeal effort. They tout Obama’s expansion of coverage to 20 million additional people and consumer-friendly coverage requirements it imposed on insurers, including abolishing annual and lifetime coverage limits and forcing them to insure seriously ill people.

The GOP bill would dismantle Obama’s requirements that most people buy policies and that larger companies cover workers. Federal subsidies based largely on peoples’ incomes and insurance premiums would end, and a Medicaid expansion to 11 million more low-income people would disappear.

The Republican legislation would provide tax credits to help people pay medical bills based chiefly on age, and open-ended federal payments to help states cover Medicaid costs would be cut. Insurers could charge older consumers five times the premiums they charge younger people instead of Obama’s 3-1 limit, and would boost premiums 30 percent for those who let coverage lapse.

House approval would give the legislation much-needed momentum as it moves to the Senate, which Republicans control 52-48 but where five Republicans have expressed opposition. Trump used Monday’s trip to single out perhaps the measure’s most vociferous foe — Kentucky GOP Sen. Rand Paul.

“He’s a good guy,” Trump said of one 2016 rival for the GOP presidential nomination. “And I look forward to working with him so we can get this bill passed, in some form, so that we can pass massive tax reform, which we can’t do till this happens.”

Enactment of the health care bill would clear the way for Congress to move to revamping the tax code and other GOP priorities. Defeat would wound Trump two months into his administration and raise questions about his ability to win support from his own party moving forward.

Among the disgruntled were GOP lawmakers in the hard-right House Freedom Caucus, though the strength of their opposition was unclear. The group has seemed to have around 40 members, but that number may be lower now and some have expressed support or an open mind for the bill.

Caucus leader Rep. Mark Meadows, R-N.C., an outspoken opponent, said the group was not taking a formal position on the measure. That could indicate that a significant fraction of its members were not willing to vow “no” votes.

Meadows said he believes the House will reject the bill without major changes.