[R]epublicans in the House of Representatives filed a lawsuit seeking to have the payments declared illegal, and the Trump administration has repeatedly refused to commit to their continued payment.

The result is that insurance firms across the country are warning that they will either have to hit customers with large rate increases to make up for the risk of payments being cut off, or will have to stop serving all or part of the exchange system entirely.

Republicans have insisted that the ACA is a flawed system that is collapsing under its own weight, but repeated statements from nonpartisan analysts and from insurers themselves indicate that the biggest problem facing the marketplace right now is uncertainty about the government's position when it comes to supporting the exchanges.

In prepared remarks delivered before a House Ways and Means Committee hearing on the Department of Health and Human Services' budget request Thursday, Chairman Kevin Brady came out and called for Congress to specifically allocate money for the CSR payments. [...]

"As the Senate considers the AHCA, we must work together to deliver an expedited solution to help stabilize the insurance market and help lower premiums for Americans trapped in Obamacare today. We should act within our constitutional authority now to temporarily and legally fund Cost Sharing Reduction payments as we move away from Obamacare and toward a patient-centered system that truly works for the American people."

He also indicated that he accepts the claim of insurance firms that uncertainty about government support for the ACA is part of the problem with the market right now.

"Insurers have made clear the lack of certainty is causing 2018 proposed premiums to rise significantly," he said. "When these payments are funded by Congress, families trapped in Obamacare should expect these proposed premiums to be reduced significantly."

Brady's statement seems, at least implicitly, to suggest that the effort to replace the ACA with the GOP-sponsored American Health Care Act may not come to fruition in time to rescue the health insurance markets.