Melissa Dodge, a single mother of four in Derby, Kan., who works part time as a restaurant hostess and is also stuck in the coverage gap, said she was struggling to get by as she tended to the complex medical needs of her daughter and everyday tasks like school drop-offs. Her doctor is careful not to order lab tests for her because of the potential for unaffordable costs, Ms. Dodge said. “It’s a massive source of anxiety,” she said of not having health insurance. “There’s a fear to it that I refuse to allow to run my life. But it’s there. And I can’t not acknowledge it.” Mr. Hawkins conceded that the politics of the Affordable Care Act had shifted with fading Republican opposition to the law, leaving it as a less potent issue to campaign against. “I just don’t think it has a punch that it once had,” he said. Ms. Kelly said that if supporters of expansion failed in the current legislative session, they would test the issue on the campaign trail this year. “This will be the No. 1 election issue,” she said. Ms. Kelly predicted that opponents of expansion were fighting a losing battle. “They’ve painted themselves into a corner,” she said. “And I think they’re having a hard time finding a face-saving way of getting out.”