Mr. Trump, Sec. Clinton, how will you fix Obamacare?

Hillary Clinton and Donald Trump square off tonight in their second debate. A glaring omission from the first presidential clash was any question about how the two major-party nominees would handle the unfolding disaster that is Obamacare.

They need to be asked, because the disaster is real, and one of them will have to deal with it.

In just the past two weeks, President Obama’s biggest accomplishment has suffered setbacks in its marketplaces on top of those that came down like hammer blows earlier this year and last.

State regulators have approved yet another big hike in insurance rates in Delaware, on top of double-digit increases already announced in Colorado, Connecticut, Washington, D.C., Maryland, Michigan, New York, Oregon, Tennessee and Virginia. Some customers will face double-digit increases in other states as well.

Large insurers have been quitting the exchanges all year because their losses are huge. Some are aggressively lobbying or suing for a bailout by taxpayers. As some insurers bail out, fewer and fewer are left, which makes future rate increases ever likelier.

Residents of 13 rural Iowa counties learned Friday that they will have just one insurer as an option on the Obamacare exchange. Just before that, 20,000 Nebraskans learned they would lose their plans as Blue Cross-Blue Shield pulled out of their state. Tennessee’s largest insurer is pulling out of the state’s three largest markets, despite being granted a record 62 percent rate increase for 2017.

Six insurers either pulled out or scaled back operations in Arizona, leaving only two in Phoenix and only one in some rural counties. Last month, New Jersey’s Obamacare co-op became the seventeenth out of 23 nationwide to close its doors.

Obamacare’s exchanges are collapsing, and in the process doing great damage to the individual insurance market. The next president will have to handle the mess. He or she might justly repeat the common refrain, “Thanks, Obama!”

It is also important to note that Obamacare’s deleterious effect on this market has very little connection to the gains that the White House keeps pointing to in the national uninsured rate. Yes, that rate, at 11 percent, is down from 14.6 percent, where it stood in 2008. But most of that net gain, and as much as 97 percent of it in Obamacare’s first year, stemmed from the decision to make able-bodied adults without children eligible for Medicaid in many states. The net gains in the uninsured rate have had little to do with Obamacare’s ham-fisted and destructive interference in the individual insurance market.

This means a big rollback of this portion of Obamacare would not undo most of its touted gains. It should not be difficult, even for a President Clinton, should she win, to take this action. The chief gripe about Obamacare from the start was not that it insured too many poor people, but that it wrecked an entire insurance market that had been working well for millions of others.

Obama’s pride will probably even now prevent him from fessing up to his failure. But his successor, Democrat or Republican, will suffer no such personal connection to the law. The next president could roll it back so it continues to do what at least seems to be working from a statistical point of view. Or he or she could decide it’s easier just to give a huge bailout to the insurance companies and pretend the problem doesn’t exist.

Either way, the next president has to have a plan to deal with this crisis, and both candidates should explain what they’d do. Unless such questions are asked in tonight’s debate, the insurance-buying public will remain in the dark about what is sure to be one of the most pressing domestic challenges for the next administration.

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