Methodology
We built upon a simple premise: Republicans who were elected to the House in congressional districts that Hillary won in the presidential race would be vulnerable in 2018.
Daily Kos did the work in identifying such districts for the presidential race. We mapped that against the results in the congressional races from the New York Times. Comparing these, we estimated the number of Hillary voters who must have crossed over to vote for the Republican congressional candidate.
Now came the hard part. To calculate the number of ACA participants by district, we broke down each district into its county components. Where counties were part of more than one congressional district, we drilled down to the precinct level where such data was available. In other cases, we allocated proportionately based on population. Our main data source, for those states that used the Federal exchange was the CMS.gov site from the Centers for Medicare and Medicaid Services with detailed demographics about those enrolled in the Affordable Care Act. For states with their own exchanges, we used their enrollment statistics by county, where available.
To calculate the beneficiaries of Medicaid expansion, we used data from the comprehensive Department of Health and Human Services website. DHHS also provides estimates for those who would be eligible under Medicaid expansion in states that opted against expansion.
We filled the gaps in our data where necessary from the work of the Kaiser Family Foundation and HealthInsurance.org which has excellent state by state summaries and latest developments.
Finally, we calculated the strength of the HealthVote coalition: Crossover Hillary voters + ACA enrollees + Medicaid beneficiaries and compared it to the votes needed to defeat the Republican incumbent. This gave us the particular Congressperson’s Vulnerability Index.
This gave us the Top 25 House members in terms of vulnerability and an action plan to hold their feet to the fire of healthcare rights for all Americans.