Ohio GOP Senate primary is first, big midterm test of Trump's influence

Ohio voters head to the polls Tuesday to decide on their nominees for the U.S. Senate – with the tight, closely-watched Republican primary taking center stage.

Five major candidates are vying for the GOP nomination: memoirist and venture capitalist J.D. Vance, former state Treasurer Josh Mandel, former state GOP Chair Jane Timken, investment banker Mike Gibbons, and state Sen. Matt Dolan.

For months, the competition was overshadowed by a battle to receive the endorsement of former President Donald Trump, which ultimately went to Vance several weeks ago.

After struggling to break away from the pack, Vance saw surges in fundraising and his poll numbers in the days leading up to the primary, thanks largely to the so-called Trump bump. Tuesday's results will be the first test in this election cycle of the efficacy of Trump's endorsement in a tight primary race.

Heading in to Tuesday, Real Clear Politics' poll average shows Vance holding on to a narrow lead with 26% of the vote, followed by Mandel with 22.5%, Dolan with 21.5%, Gibbons with 15%, and Timken with 7%. All five candidates believe the race could be theirs, especially with a significant number of voters undecided.

On the other side, 10-term Rep. Tim Ryan will likely be the Democratic nominee to fill the seat being vacated by retiring GOP Sen. Rob Portman.

Ryan is in a race against Democratic attorney and organizer Morgan Harper, and businesswoman Traci TJ Johnson, both of whom he is expected to defeat handily. 

Ohio's Republican Gov. Mike DeWine is also poised to emerge victorious from his primary against U.S. Rep. Jim Renacci and Joe Blystone, a farmer and MAGA supporter. DeWine is competing for his second term. Trump has not weighed in on DeWine's race, despite hinting in the past that he is not a fan of the governor's leadership.