In many states, Republicans maximized gains in the House by spreading GOP voters across as many districts as possible. Typically, that left Democrats with around 40 to 45 percent of the vote in those districts, making them difficult under normal circumstances for the minority party to contest.
But this election year is anything but normal. Many of the once-secure 55-45 Republican districts are very much in play, even in states that have not had competitive congressional races since 2012, the year new maps were installed. And North Carolina and Ohio — where Democrats chose nominees in primaries on Tuesday — are turning into the prime examples.
Neither national party has spent money in North Carolina or Ohio in the past two elections. But operatives in both states now rattle off a half-dozen Republican districts that could become fierce battlegrounds this fall, including the fast-changing suburbs of Cincinnati, Charlotte, Columbus and Raleigh. President Donald Trump won less than 55 percent of the vote in each of the seats in 2016 — and some of the Republican incumbents have been caught by surprise by the ferocity of their competition.
“The math that was used to create these districts was the same math that was calculated in the anti-Obama era,” said Paul Shumaker, a Republican consultant based in North Carolina. But now, he continued, “because of the way the maps have been drawn and the environment that Republicans are facing, you have a whole bunch of Republicans who have never been in a competitive race in their life, who are running [in one] right now.”
In Epic Journey: the 2008 Elections and American Politics, we wrote:
House elections are different from Senate elections because members represent districts whose shapes change over time. Before 2006, many Democrats worried that unfair district lines would block a Democratic takeover. The redistricting after the 2000 census did protect House incumbents, making it harder for the minority party to score gains. Nevertheless, some commentators overstated the effect of computer-crafted districts. No matter how clever a redistricting scheme may be, demographic and political changes may blunt its impact over time. Young people and new citizens enter the electorate. Old voters die. Other voters move around or change their party preference. Such shifts were on display in New York State, where a bipartisan gerrymander had once seemed to guarantee the GOP a certain minimum of House seats. But by 2006, shrinking Republican numbers helped nudge three GOP seats into the Democratic column. Texas, Florida, and Pennsylvania had notorious Republican gerrymanders that backfired. The Wall Street Journal reported shortly after the election: “Republican leaders may have overreached and created so many Republican-leaning districts that they spread their core supporters too thinly. That left their incumbents vulnerable to the type of backlash from traditionally Republican-leaning independent voters that unfolded this week”[i]
[i] Jeane Cummings, “Redistricting: Home to Roost. How Republicans’ Gerrymandering Efforts May Have Backfired,” Wall Street Journal, November 10, 2006, A6