The Republican party may have an advantage over the Democratic party in maintaining control of the House for ten years.
Every ten years, Congressional district boundaries are redrawn to reflect population changes. Each state determines its own process for redrawing Congressional districts. Usually the plan is created or approved by the state legislature and in some case the Governor as well. Six states use an independent or bipartisan commission and seven states have only a single representative for the entire state because of their low populations.
A new analysis from the Brennan Center for Justice shows that the recent redistricting put in place for the current election increased the number of seats favoring Republicans by eleven, to 241. The primary reason is that “173 seats were redistricted by GOP legislatures, while only 44 were redistricted by Democratic legislatures” according to Dylan Matthews of the Washington Post (“Why redistricting could doom House Democrats”)
Of course there are many reasons this may not translate to a 10-year Republican-controlled House. Here’s just two. First, candidates matter and will dictate what happens in a number of districts. Second, some of these districts may see a population shift in coming years that reduces the Republican lean.