“A different health care issue has emerged for Democrats, in sync with the party’s pitch to … middle-class voters … high out-of-pocket costs for people already covered. Democrats call it ‘underinsurance.’ After paying premiums, many low- and middle-income patients still face high costs when trying to use their coverage. … [T]he value of a health insurance card is being eaten away by rising deductibles … Several liberal-leaning organizations have recently focused on the issue.”