Ohio just pushed the country past a symbolic threshold: it’s become the 25th state to pursue expanding Medicaid under the president’s health-care law, making the nation’s states evenly split on the issue for the first time.

As of the start of the month, 24 states had opted to forge ahead with the expansion and 26 had not, according to the Kaiser Family Foundation, a health policy news and analysis nonprofit. Ohio was among those that were not expanding health care to more low-income adults, though Republican Gov. John Kasich wanted it.

But a seven-member board that considered his request got its fourth pro-expansion member, Rep. Ross McGregor (R), on Monday morning and had voted 5 to 2 to forge ahead by the afternoon, according to local reports. Some are considering suing the state, according to The Columbus Dispatch. Many oppose the expansion on principle, as it also represents an expansion of the size of government.

States that approved the expansion get federal assistance.

Such “increases in federal funding will greatly outweigh any potential increases in state expenditures and will have positive economic effects, increasing employment and state general revenues,” the Kaiser Family Foundation found in a July report.

The expansion of Medicaid would affect some 10 million people, just over one third of whom live in the 24 states that have opted in. Some 275,000 adults could also benefit from the Ohio decision, according to the Kasich administration’s calculations, which have been verified by Politifact.

Of the 24 states with unified Republican capitals—where the GOP controls the House, Senate and governor’s mansion—only three had opted for the Medicaid expansion. Ohio makes it four. And only seven of the nation’s 30 Republican governors were overseeing a Medicaid expansion. Kasich is now the eighth.

The Affordable Care Act expanded eligibility for the low-income health care program to nearly all non-elderly adults with incomes up to 138 percent of the federal poverty level. But in a landmark ruling in the summer of 2012, the Supreme Court said states could opt out of expanding the program. The nation’s states are now evenly split on expansion.