SALT LAKE CITY — Utah voters like the idea of expanding Medicaid coverage in the state, with unofficial results Tuesday night showing Proposition 3 passing 55 percent to 45 percent.

Proposition 3 calls for expanding Medicaid eligibility to every Utahn in a household earning 138 percent or less of the federal poverty level, and paying for that expansion by raising the state sales tax from 4.7 percent to 4.85 percent on nonfood purchases.

The Proposition 3 campaign, called Utah Decides Healthcare, has estimated the tax increase would raise $91 million in state money, thereby triggering more than $800 million in matching federal funds to pay for the costs from about 150,000 projected new enrollees in the federal health insurance program.

"We're obviously feeling really good about the results coming in tonight. This is the culmination of six years of work here in Utah," said RyLee Curtis, campaign manager for Utah Decides Healthcare.

By 10:30 p.m., 10 counties had finished submitting total voting numbers on Proposition 3, but all were rural. Counting remained open in Utah's four largest counties, with the published votes showing voters in Salt Lake, Davis and Weber counties favoring the initiative and Utah County voters coming down against it.

Curtis said the campaign was "feeling good about the votes" late Tuesday.

She said she felt Proposition 3 had strong appeal statewide because of how many rural Utahns are uninsured.

"I can tell you we're confident we've run the best campaign we possibly could have," Curtis said.

The Affordable Care Act mandated that each state expand Medicaid eligibility to everyone at 138 percent or less of the federal poverty level. But a 2012 Supreme Court ruling made Medicaid expansion optional on a state-by-state basis.

Full Medicaid expansion has failed multiple times in the Utah Legislature, including lawmakers' defeat of Gov. Gary Herbert's Healthy Utah expansion plan that he lobbied for in 2015.

In 2016, state lawmakers passed a limited form of expansion, designed to bring Medicaid eligibility to 4,000 to 6,000 of extremely low-income Utahns, including the homeless, with a focus on bettering their behavioral health and substance abuse treatment options.

This year, the Legislature OK'd a bill instructing the Utah Department of Health to submit a federal waiver that seeks to offer Medicaid eligibility to all Utahns in households earning 100 percent of the federal poverty level, expanding coverage to an estimated 70,000 to 90,000 Utahns.

A waiver is needed with that bill because it seeks a full 90 percent to 10 percent federal matching rate without fully expanding coverage defined by the Affordable Care Act.

The push for full Medicaid expansion in Utah has been met with very little organized opposition this year. The only group that has reported any significant campaigning against the measure this year is a political issues committee called No on Proposition 3, which took about $35,000 in in-kind canvassing and advertising help from Americans For Prosperity, a conservative political advocacy group, in late September and early October.

However, the push has had its critics, including Rep. Jim Dunnigan, R-Taylorsville, who was behind the narrowly targeted Medicaid expansion for Utah's extremely poor which passed in 2016.

Dunnigan said late Tuesday it appeared Proposition 3 would pass, and that "the upside is it will provide health care to quite a few low income adults."

But he said the worrisome risk is that "there's no top end or limit to what it could end up costing the state."

"Just because there's a sales tax increase associated with it doesn't mean that's going to be adequate to fund the expansion," Dunnigan told the Deseret News. "That's a big risk."

He also said that other states that have expanded Medicaid have found it entails paying for the coverage of "more people, and at a higher cost, than has been projected" there, and that the same could conceivably happen in Utah.