Gov. John Hickenlooper on Tuesday continued his marathon assault against Republican efforts to replace the Affordable Care Act.

The Democrat focused on “ongoing threats to undermine and defund our health care system,” underscoring President Trump’s proposal to default on making cost-sharing reduction payments on health insurance.

“On a state level we see firsthand in very sharp contrast of what the impact is not just on the insurance company and seeing the increase in the potential increase in premiums, but we hear stories about families and individuals in the markets who are faced with un-makable decisions,” Hickenlooper said on a conference call with health professionals.

The critical Obamacare payments to insurers could throw an already chaotic health insurance system into flux, potentially raising customers’ costs and leaving tens of thousands without coverage next year. Trump could scrap the payments as early as this week.

The payments – worth about $7 billion – is within the president’s discretion to eliminate.

The cost-sharing subsidies lower out-of-pocket costs, including co-payments and deductibles, for low-income ACA customers. The payments help cover about 7 million in the nation. Insurers might exit the market if they face the uncertainty of losing those subsidies, or they could hike premiums to cover the difference.

“This is state-sponsored sabotage, plain and simple,” said Andy Slavitt, senior advisor at the Bipartisan Policy Center and former acting administrator for the Centers for Medicare and Medicaid Services, who joined the call Tuesday morning.

“The president of the United States is suggesting that he may default on these payments to purposely spite people’s premiums,” Slavitt continued.

Hickenlooper has taken a bipartisan approach to opposing federal health reform efforts, repeatedly joining with Republican Gov. John Kasich of Ohio and other governors in urging that both sides of the aisle work together on a fix.

“One of the big problems with all of the Republican bills that have come forward so far is they were developed with a small number of people without any collaborative approach from even the rest of the Republican senators, but certainly no input from Democratic senators,” Hickenlooper said. “It’s to be expected that you’re going to have a very one-sided proposal.”

Hickenlooper also made the case for preserving the individual mandate, arguing that it keeps people in a larger insurance pool, which restrains inflation of premiums and copays.

“Making sure that the federal government doesn’t back away from requiring the mandate, that they charge that penalty of $695, that’s part of also making sure that we continue this improvement of the stabilization of the private markets,” Hickenlooper said.