The Republican president's shadow also loomed over primary contests in four other states, none bigger than Kansas, where Trump roiled the governor's race by opposing the GOP incumbent on the eve of the election.
A Monmouth poll last week showed the race was essentially a dead heat, down from a double-digit advantage for Balderson a month ago.
Democrat Danny O'Connor, the Franklin County recorder, speaks to the media alongside his fiancee Spenser Stafford, after Stafford voted at the Noor Islamic Cultural Center, Tuesday, Aug. 7, 2018, in Dublin, Ohio.
The night before the rally, Trump took to Twitter to attack LeBron James, calling the National Basketball Association star dumb just days after James, an OH native, poured tens of millions of his own dollars into the opening of an innovative public school in Akron.
Balderson got a majority of the vote, besting upstart Democrat Danny O'Connor perhaps thanks to a surge following a recent rally on his behalf by President Trump.
The pro-Balderson effort has focused largely on motivating Republican voters by casting O'Connor as extreme.
O'Connor and his Democratic allies railed against the tax plan, casting it as a giveaway for the rich that exacerbates federal deficits and threatens Medicare and Social Security.
President Donald Trump rips LeBron James in late-night tweet
Along with Jordan, a number of other athletes spoke out in support of James. James tweeted Saturday about the I Promise school , saying "Love you guys".
Republican strategists in Washington are also watching Kansas closely. Senate Republicans had hoped to make MI, a state which Trump carried, competitive, but it's fallen down the list of top targets for 2018. "VOTE TUESDAY!" Trump tweeted. Democrats weren't even supposed to be competitive here.
Kansas is a deep-red state - Trump won there by 20 percentage points in 2016 - and any Republican would be favored in the gubernatorial election in November.
Whitmer will face Republican Bill Schuette, who was endorsed by Trump, in November. Bernie Sanders and NY congressional nominee Alexandria Ocasio-Cortez, who catapulted to fame when she defeated the No. 4 House Democrat in a June primary.
And while Trump claimed credit for the tight victory in a Tuesday night tweet, it's likely Kasich who deserves the game ball for helping Balderson hang on in enough suburban territory to pull out the win.
Senate contests in Missouri and MI were coming into focus as two vulnerable Democrats, Missouri's Claire McCaskill and Michigan's Debbie Stabenow, were expected to easily claim their party's nominations.
The five-way Democratic primary featured labor lawyer Brent Welder, who campaigned recently with self-described democratic socialists Vermont Sen. Other top candidates include Sharice Davids, an EMILY's List-endorsed former MMA fighter attempting to become the first Native American lesbian in Congress, and Tom Niermann, a teacher running a more moderate campaign with a long list of local officials' endorsements.