This week on Capitol Hill, Centers for Medicare and Medicaid Acting Administrator Andy Slavitt testified before the House Subcommittee on Oversight and Investigations about several billions in federal taxpayer dollars that were used to create state-based exchanges, many of which failed.

It should be the role of all lawmakers to investigate potential waste and abuse, and to seek to protect taxpayer dollars. Everyone knows that Obamacare is a deeply partisan issue, but even those who support it should not scoff at the idea of oversight. They should recognize that better oversight would only make the law more efficient and more legitimate.

But sadly this hearing just showed how far apart the two sides are on this issue.

While supporters of the law wasted time with political talking points and softball questions about the law’s coverage expansion, Obamacare critics asked meaningful questions about what happened to the misused funds and if and how they can be recouped.

The point of the hearing was to investigate monies spent on attempts to expand private insurance coverage through state-based exchanges and other efforts like the onsumer-oriented and operated plans or CO-OPs.

These efforts are an obvious weak spot in the law: Any net increase in private insurance coverage under Obamacare has been paltry.

While the exchanges have enrolled millions, about the same number of Americans have lost insurance coverage through their employers or through the cancellation of their old plans. And this year the government revised down their original estimate of 21 million to 10 for 2016 coverage through the exchanges.

At first many exchanges, including the federal, suffered from technical problems and glitches on their online platforms. Most of these issues have now been resolved, but not without cost: The launch issues made enrollment almost impossible in some states that created their own exchanges, resulting in the closure of several state exchanges who defaulted to the federal exchange last year.

Overall, the federal government spent about $4.6 billion building state-based exchanges.

The CO-Ops, too, have clearly been a failure. Of the 23 that were created, today a dozen have announced closures. In some cases, like Health Republic NY that Rep. Chris Collins (R-N.Y.) mentioned at this latest hearing, they were one of the biggest insurers on the state’s exchange. Their closures mean hundreds of thousands of people must switch insurance plans. And for taxpayers – millions in lost funds.

How then, can supporters of the law say (rightly) that the uninsured rate in the United States is at an all-time low? Simple: The law’s Medicaid expansion is responsible for almost all gains in insurance coverage, to the public cost.

The worst example of off-topic political grandstanding in this hearing came from Rep. Kathy Castor (D-Fla.) who asked Mr. Slavitt’s advice for dealing with the “unreasonableness” of others in the state of Florida who would not expand Medicaid. She said she hoped a coalition would come together to expand the program yet.

As deserving as the Medicaid expansion is of a cost-benefit analysis, that’s not what this hearing was about.

This hearing was meant to be about holding Centers for Medicare and Medicaid Services accountable for the way billions of dollars in grants were spent by states, specifically on state-based marketplaces and the law’s attempt to expand private insurance.

Although Slavitt assured lawmakers that CMS has mechanisms in place to prevent and monitor the misuse of funds, we heard relatively little about what those are or how they work. Slavitt promised that the federal government was in negotiation with several states about paying back misused funds, but success is yet to be seen.

It’s not just important that lawmakers of all political stripes support and continue this investigation for the sake of recouping taxpayer dollars, but it’s critical that they discover how such terrible waste of funds happened in the first place. At the end of the day, the money has gone out and Obamacare’s implementers have little to show for it. Someone has to answer for that.