The Democrats, trying to stiffen their party’s spines on the contentious issue, say it’s unfair to bar illegal immigrants from paying their own way in a government-sponsored exchange. Legal immigrants, they say, regardless of how long they’ve been in the United States, should be able to get government-subsidized health care if they meet the other eligibility requirements.

“Legal permanent residents should be able to purchase their plans, and they should also be eligible for subsidies if they need it. Undocumented, if they can afford it, should be able to buy their own private plans. It keeps them out of the emergency room,” said Rep. Michael M. Honda, California Democrat and chairman of the Congressional Asian Pacific American Caucus.