This week, voters will go to the polls and cast their ballots in the midterm elections. These elections are typically viewed as referendums on the current president's performance in office, and often result in a change in balance of power. This week, Democrats are working to gain at least the 23 seats they need take back control of the House, as all 435 House seats are up for re-election. Voters will also weigh in on a third of all Senate seats and 36 governorships across the country.
Here are five facts on the upcoming midterms, and how past voters have changed the course of political history:
1. In the past 100 years, there have been seven Congresses where one party controlled the Senate and the other controlled the House. This includes the 72nd Congress (1931–1933), 97th Congress (1981–1983), 98th Congress (1983–1985), 99th Congress (1985–1987), 107th Congress (2001–2003), 112th Congress (2011–2013), and 113th Congress (2013–2015).