(NewsNation Now) — State legislatures and independent commissions have begun the process of drawing new state house and senate districts, as well as new congressional districts. Politicians seeking reelection have a stake in the process, since winning or losing may depend on how districts in their state are drawn.

Republicans have a big advantage on flipping the House back red even before the polls open.

Every 10 years, a congressional district is redrawn and the new district is supposed to reflect population changes in cities and towns. However, in reality, what usually happens is the party in control of the state redraws the lines in a way that benefits that party. The process is called gerrymandering.

Democrats in Maryland essentially cut the Republican parts of a district right out of it and in Texas, Republicans did the reverse. This year, gerrymandering is having an outsized impact because of just how tight the margin is for control of Congress. It’s so close and already Republicans have redrawn enough districts to flip control of the House.

Currently, Washington state’s bipartisan redistricting commission is redrawing political maps.

Under state law, the Washington Supreme Court must come up with 10 U.S. House districts and 49 state legislative districts that will be in place for the next decade, starting with the 2022 midterm elections.