Back in 2009, when Congress was debating the Affordable Care Act, many liberal Democrats felt it did not go far enough — that it should be even more sweeping, even more expansive, even more costly.

Tom Harkin, D-Iowa, one of the Senate's most liberal Democrats and a veteran of many legislative battles, urged his colleagues on the Left to go ahead and pass the bill. "The key to this is that this modest home, we can put additions onto it in the future," Harkin told MSNBC's Rachel Maddow in December 2009. "But if we don't have the starter home, we're never going to be able to put those additions on."

Harkin's view prevailed, and many Democrats came to view Obamacare as a starter home. Now, even though the Affordable Care Act still faces an uncertain future in the courts, they want to start building the additions.

The first addition is the result of a problem Obamacare itself made worse.

"A different healthcare issue has emerged for Democrats, in sync with the party's pitch to workers and middle-class voters ahead of next year's elections," reported the Associated Press a few days ago. "It's not the uninsured, but rather the problem of high out-of-pocket costs for people already covered. Democrats call it 'underinsurance.' "

The problem is that the deductibles on many Americans' health insurance policies have shot up so high that as a practical matter they can't afford care. If a couple had a deductible of, say, $500 in the past, and it's now $3,000, that couple has to spend a lot of money out-of-pocket before reaping the benefits of coverage. And the higher the deductible, the more likely a person is going to skip some sort of needed treatment or medicine because he or she can't afford the up-front costs.

"About a quarter of all non-elderly Americans with private insurance coverage do not have sufficient liquid assets to pay even a mid-range deductible, which at today's rates would be $1,200 for single coverage and $2,400 for family coverage," the Wall Street Journal reported in March.

So now, many of the same groups that agitated for Obamacare are agitating for new government spending or tighter controls on the insurance industry and businesses to "solve" the problem. But perhaps the first question to ask is: How did those deductibles get so high in the first place?

The answer is Obamacare.

Obamacare's upward pressure on deductibles started in the law's first year. By the fall of 2010, six months after President Obama signed the bill into law, Obamacare dictated that insurers could no longer impose lifetime caps on payments, could not deny coverage to people with pre-existing conditions, and had to insure adults up to the age of 26 on their parents' policies.

Those provisions raised the insurers' costs, and since then some additional cost-increasing Obamacare provisions have become law. Sure enough, deductibles began to increase significantly. The pro-Obamacare group Commonwealth Fund measured adults for whom the insurance deductible represents five percent or more of annual income. In 2003 and 2005, Commonwealth Fund found, three percent of adults were in that category. In 2010, the figure doubled, to six percent. In 2012, it rose to eight percent. In 2014, it rose to 11 percent.

Republicans have long predicted the increase in deductibles. But most analyses from liberal groups pay scant notice to the effect that Obamacare's edicts are having on deductibles. Instead, groups on the left like the Center for American Progress are coming up with proposals for new mandates, like more free preventive services and a "shared savings rebate," in which employers would be forced to turn over some healthcare payments to employees, as solutions to the problem.

For the liberal groups, it's time to start building additions to the starter home.

Meantime, it appears a new round of health premium increases is underway, spurred in part by the fact that the Obamacare risk pool includes more older and sicker — and more expensive to insure — people than originally estimated. That doesn't bode well for the deductible problem.

"The big rate increases have begun," notes the respected insurance analyst Bob Lasziewski. "So how are they going to cut deductibles in the face of the increases we are starting to see?"

As the Associated Press noted, some Democrats see high deductibles and out-of-pocket costs as an issue they can exploit in 2016. But Republicans have a sharply effective response: Why should voters trust Democrats to solve a problem they made worse in the first place?