Elections are not competitive. More than 80% of U.S. House districts are completely safe for the party that holds them, and only a small fraction will be true toss-ups in 2018. As a result, millions of Americans are perpetually represented by politicians they oppose, with little hope of changing things at the polls.
Outcomes are distorted. We project that in 2018, Democrats are only likely to win the House if more than 55% of voters want a Democratic House. Many state delegations are even more skewed, as in Massachusetts, which elects 9 Democrats and 0 Republicans, even though nearly 40% of its voters prefer the GOP.
Representatives are more polarized than voters. Voters in general elections must choose between polarized candidates selected by highly partisan primary voters, leaving less partisan Americans without a route to representation.