The midterms are seen as a crucial indicator of the direction of the U.S. "If the Republicans do well, then across Europe, people will be thinking Trump is not just a passing phase," says one analyst.
This election season, groups that are unable to vote — like youth and undocumented people — are solidifying their impact on America's democratic process.
Keeping control of the House would validate President Trump's governing style and mean full speed ahead for his agenda. But if the GOP loses its majority it will need to protect Trump.
If Democrats fail to take back the House and make significant gains at the state level, they'll be shut out just as they were in 2016, with little say in legislation and judicial appointments.