Yet in eight politically significant counties in Michigan, Wisconsin, and Pennsylvania with a high concentration of suburbs, the uninsured rate was half the national number — or 5.2%. And 81.3% of those with insurance had private coverage.

Typically, political campaigns want to run on policies that will benefit a wide number of people, while leaving most others no worse off. But in these crucial suburbs, Democrats will be advocating drastic solutions to help a small percentage of residents while severely disrupting the lives of the vast majority of the population. If Warren were the nominee, Republicans could run fact-check proof ads in every one of these areas saying she wants to eliminate their private coverage within her first term, and it would be true for most people who live there.

As part of this analysis I looked at counties in Pennsylvania (Bucks, Chester, and Delaware) that border Philadelphia; the so-called WOW counties of Wisconsin surrounding Milwaukee (Waukasha, Ozaukee, and Washington); and Oakland and Macomb counties in Michigan, which include suburban Detroit. Four of the Congressional seats that Democrats flipped in 2018 came from one of these counties, and they all figure to play a key role in next year’s election. Were Democrats to build on their 2018 performance in these areas and flip Pennsylvania, Michigan, and Wisconsin, they would win the White House. But a Democratic failure in these areas would likely mean a second term for President Trump.