President Donald Trump’s plummeting popularity has promised a bloodbath for Republicans in this year’s midterm elections. To head off that debacle, party leaders in red states have set off an arms race of political gerrymandering. They’ve made an unprecedented move to redistrict their states before the next census to create new, safe GOP districts that might allow the party to preserve its control of Congress in November’s midterm elections. Blue states like California have responded in kind.