PORTLAND, Me. — Brandy Staples, a 39-year-old breast cancer survivor, had expected to become eligible for Medicaid coverage this month after Maine voters approved an expansion of the program last fall. Instead, she found herself in a courtroom here on Wednesday, watching the latest chapter unfold in a rancorous, drawn-out battle over whether she and thousands of other poor people in the state will get free government insurance after all.

Ignoring the binding vote, Gov. Paul LePage has refused to expand the program, blasting it as a needless, budget-busting form of welfare. He vetoed five expansion bills before the issue made the ballot, plus a spending bill this month that provided about $60 million in funding for the first year. Earlier this month he went so far as to say he would go to jail “before I put the state in red ink” by adding at least 70,000 more low-income adults to the state’s Medicaid population of 264,000.

The showdown is on the extreme end of tensions playing out this election year in a number of Republican-controlled states that have resisted expanding Medicaid under the Affordable Care Act. Following Maine’s lead, advocacy groups in Idaho, Nebraska and Utah have gathered enough signatures to get Medicaid expansion measures on their state ballots this November, although Nebraska’s have yet to be certified. Already, two prominent Republicans there, a state senator and former state senator, havechallenged the effort in court.