The 2020 elections will be an acid test for Texas politics. Did the results in 2018 mark a new trend toward more competitive general elections or a one-time swerve away from the steady quarter-century pattern of Republican dominance?

To answer that question, we looked beyond who currently represents each congressional or legislative district and created our own Heat Index — a measure of whether each district generally favors Democrats or Republicans in statewide elections. Statewide elections are those from president down to the top courts in Texas — races decided by all Texas voters, and not just some of them.

Here is how we calculated the Heat Index For each congressional and legislative district: Average percentage vote for Republican statewide candidates Average percentage vote for Democratic statewide candidates Heat Index = — Here is how we calculated the Heat Index For each congressional and legislative district: Heat Index = Average percentage vote for Republican statewide candidates Average percentage vote for Democratic statewide candidates —

This is a better way to explore the politics of the districts. Here’s why: Seats will sometimes flip for unusual reasons — a lackluster candidate, a scandal or issues having little to do with who’s on the ballot. Looking at how each party fares on average in a district in statewide races ignores that noise to highlight broader political trends.

Take a look at how the Heat Index has changed in some of Texas’ congressional, state House and state Senate districts over the last 18 years. Then look up how the districts where you live have changed.