In most states, undocumented immigrants are barred from government-subsidized health care programs, such as Medicaid, the federal program for the poor and disabled.
California is a notable exception. Since 2016, the state has provided Medicaid to children under 18 regardless of their immigration status. In its new budget, California goes even further by extending the program to low-income immigrants until they turn 26.
The move has been largely greeted with a shrug. A March survey by the nonpartisan Public Policy Institute of California found nearly two-thirds of those surveyed supported Medicaid coverage for young adults without legal status.
"We've gotten relatively little, if any, organized opposition," said Anthony Wright, executive director of the left-leaning advocacy group Health Access. He said the political hurdles faced in covering all undocumented migrants stemmed more from fiscal arguments than philosophical concerns.
That accepting attitude, however, isn't widely shared.
A CNN poll conducted after the Democratic debate found nearly 60% of those surveyed nationwide opposed government-provided health insurance for undocumented migrants. While liberal Democrats were strongly in favor, nearly two-thirds of independents were opposed, as were 61% of self-described moderates.
Those, not incidentally, are the swing voters who tend to decide close elections.
"Most Americans want to make sure that their candidate for president cares about what's good for the whole country, not just what's good for one subset of people," said Lanae Erickson, a politics and policy analyst at Third Way, a center-left Washington think tank.
Trump has consistently used the immigration issue to portray Democrats as weak on border security and more concerned with immigrants than the country as a whole, Erickson said, and candidates "need to be careful they're not making his job easier."
In crafting the Affordable Care Act, Democrats were acutely sensitive to the fraught politics surrounding immigration and health care. To defuse opposition they included language barring undocumented immigrants from enrolling in insurance plans created by the law, even if they were able to pay the full cost.