(Bloomberg) -- If Democrats keep the White House comeNovember, millions of Americans could gain health-care coverage. IfRepublicans take it back, millionscould become uninsured. A new study ran the numbers under theproposals of both U.S. presidential candidates.

Donald Trump’s pledge to repeal theAffordable Care Act, President Barack Obama’s signature health-carelaw, would result in 19.7 million more people without insurance andwiden the federal deficit by $33.1 billion in 2018, according to ananalysis conducted by research group Rand Corp. and funded by the Commonwealth Fund,a nonprofit foundation.

The Republican nominee’s proposed tax credits would largelybenefit higher-income people, the study also found.

By contrast, one of Hillary Clinton’s key health-reformplans could provide insurance to as many as 9.6 million individualsand lower expenses mainly for low- and moderate-income people. Itwould come at a greater cost to the budget, increasing the deficitby $90.4 billion.

The report offers a detailed look at the policies pushed by thetwo presidential nominees in a campaign where ugly rhetoric andcontroversy have often swamped policy discussions.

The Affordable Care Act, known as Obamacare, remains a flashpoint six years after its passage, with Democrats determined toprotect it and Republicans vowing to repeal it. Thestudy, coming days before the first Clinton-Trump debate onMonday night at Hofstra University in New York, puts some numbersbehind the heated political debate.

“We’ve heard the discussion of repealing the Affordable Care Actfor many years,” said Sara Collins, a vice president at theCommonwealth Fund. “The estimates provide people with an idea ofwhat it means to retain the law versus repeal the law. By just theact of repealing, it would lead to millions of people not havingcoverage.’’

In a statement, the Trump campaign dismissed the study’sfindings as “ludicrous” and criticized its approach as a“distraction from the disaster that is Obamacare.” Any replacementto Obamacare would ensure that those now receiving support would begiven subsidies or other forms of help to purchase health insurancein the private market through Health Savings Accounts, the campaignsaid.

“Hillary Clinton will build on the health care progress we’vemade by expanding coverage to millions of Americans who need it andaddressing the costs that families face,” said JacobLeibenluft, a senior policy adviser to Clinton.

Repealing Obamacare

To evaluate Trump’s plans, Rand modeled the effects of repealingObamacare and replacing it with his proposals. The Affordable CareAct, or ACA, gave states funds to expand thegovernment-run Medicaid program for the poor, and createdmarkets where individuals could buy health plans, often withfederal subsidies. It also lets children stay on their parents’health plans to age 26, requires the purchase of health insurance,and bars insurers from excluding people who are sick, withso-called pre-existing conditions, from buying plans. Clinton’splans were evaluated as extensions of the current law.

The researchers said they asked both campaigns to help with themodeling. Clinton’s campaign provided answers, while Trump’scampaign referred the researchers to its website, they said. Bothcampaigns were given copies of the analysis before it waspublished.

Tax deduction

In his proposals, Trump would replace the ACA with a taxdeduction letting people with health plans fully deduct theirinsurance premiums from their taxes. He would move to a system ofMedicaid block grants, which would cut costs because the federalgovernment would provide states with a limited, fixed amount ofmoney. And he wants to allow insurance to be sold across statelines.

The deduction for insurance premiums would add about $8 billionin costs to the ACA repeal, increasing the federal deficit by anestimated $41 billion, while reducing the number of individualslosing coverage to 15.6 million, the Rand study found. Thededuction would lead to lower health costs for higher-incomepeople, who benefit more from reduced taxes, the researcherssaid.

“Distributionally, it benefits higher income people more thanlower income people,’’ Collins said.

Four proposals

From Clinton’s side, the researchers looked at four proposals,all of which would increase coverage and lower costs forindividuals. Three of the proposals would add to the deficit, andone would cut it modestly.

The biggest proposal, according to the study, is a refundabletax credit of as much as $2,500 for individuals and $5,000 forfamilies whose health-care costs exceed 5 percent ofincome. She also wants to fix what’s called the familycoverage glitch, which prevents some low-income families fromgetting financial assistance.

But the proposal that’s attracted the most attention recently --a government-run public option health plan to compete with privatecarriers on the ACA’s exchanges -- has some of the smallesteffects. It would provide insurance to 400,000 additional people,while cutting the deficit by $700 million. The Rand analysisassumes the plan would pay providers Medicare rates, which aretypically lower than those paid by commercial insurers, helpingaccount for its lower cost.

Copyright 2018 Bloomberg. All rightsreserved. This material may not be published, broadcast, rewritten,or redistributed.