While many Americans are obsessively following the presidential primary campaign, health policy experts are concerned about little-noticed Republican primary contests for state legislative seats that could determine the fate of Medicaid expansion in Arkansas and other states.

In Arkansas, Tuesday’s elections include several primary contests pitting Republican state lawmakers who voted for Medicaid expansion to low-income adults against GOP primary challengers who promise to end the state’s coverage expansion. Republican Gov. Asa Hutchinson needs votes from 75% of the GOP-controlled Legislature to win approval for his conservative changes in the state’s Medicaid expansion program, or else the expansion will end this year. So he can’t afford to lose any expansion allies.