Ohio voters are deciding which Republican will challenge Democratic incumbent U.S. Sen. Sherrod Brown in what's considered a toss-up November election. Polls close at 7:30 pm.
Catch up quick: Brown has been in office since 2007, all while the state has moved towards the right.
Three Republicans — state Sen. Matt Dolan, Secretary of State Frank LaRose and entrepreneur Bernie Moreno — are hoping to defeat him in November.
Between the lines: Former president Trump threw his support behind Moreno and rallied for him last weekend, but Moreno is seen as the only Trump-backed Senate candidate at risk of losing in a GOP primary.
Ohio Gov. Mike DeWine supports Dolan, whose family owns the Cleveland Guardians baseball team.
LaRose oversees the state's election system and helped organized Trump's inauguration, but could not secure the former president's endorsement.