Pennsylvania Special Election Is a Litmus Test for Midterms Listen Download Embed Share Share this on Facebook (Opens in a new window) Share this on Twitter (Opens in a new window) Share this via Email Pennsylvania’s 18th Congressional District has become a litmus test for midterm races across the country as they hold their special election Tuesday, ahead of midterms in November. ( Mary Wang ) Produced by Dana Roberson Hosted by Todd Zwillich Produced by PRI and WNYC