Even as Democrats seek the biggest expansion of health coverage in decades, as many as 23 million people could still be without insurance by 2018, the Washington Post reports. The legislation that the Senate passed Christmas Eve would leave about 8% of the population under age 65 without health insurance, according to the nonpartisan Congressional Budget Office. It would extend insurance to 31 million of an estimated 54 million who would have no coverage without the legislation, reports the Post.