The flashpoint this time is a key funding stream for the program ― one that subsidizes insurers so they can offer low-income consumers plans with reduced out-of-pocket expenses.

President Donald Trump suggested in a Wednesday Wall Street Journal interview that he and other Republicans might cut off the funds. Now Democrats are saying they’ll fight this by demanding that Congress include the money as part of a spending bill that is supposed to keep the government running past April.

Senate Minority Leader Chuck Schumer (D-N.Y.) “will be pushing hard for it as part of the negotiations,” a senior Democratic leadership aide told The Huffington Post.

An aide to House Minority Leader Nancy Pelosi (D-Calif.) said that the issue is her “top priority” in the negotiations.

The politics of the emerging conflict are complicated and unpredictable, and one possible outcome is an impasse that prevents the spending bill from passing. In other words, another government shutdown over Obamacare could be in the offing.

But the stakes in the fight are higher than normal, because withholding the money could throw insurance markets into disarray ― potentially unraveling insurance coverage for millions of people. In the Journal interview, Trump said he hoped that would motivate Democrats to negotiate with him over repeal.

Democrats, predictably, are having none of it. They say they are happy to talk about modifying the health care law ― but only if Republicans agree to leave the bulk of the coverage expansion in place, and only if Trump stops trying to sabotage the law.

The payments in question ― so-called cost-sharing reductions, or CSRs ― reimburse insurers for providing more generous coverage to consumers with incomes below 250 percent of the poverty line. That’s $61,500 for a family of four.

The 2010 Affordable Care Act instructs the federal government to make these payments, but it does not actually appropriate the money. The Obama administration paid the money anyway, saying it had…