The Virginia governor’s race Tuesday is not the only one that could have an effect on the future makeup of Congress.

Over the next four years, the parties will fight state by state to determine the next decade of congressional power — 36 of those governorships are up next year.

In 28 of the 38 states with gubernatorial races in 2017 and 2018, the governors have the power to veto new congressional maps. Over the past decade, the number of governorships held by Democrats was cut nearly in half, allowing Republicans to draw maps that ensured their dominance in the House.