However, if Balderson keeps the victory, it will be short-lived - the seat will go up for election again in November for the general midterm election.
But just as with other special elections in the 2018 cycle where Democrats waged a competitive race on red turf, from Alabama's Senate seat to Pennsylvania's 18th District, Republicans started to see danger signs as the election drew nearer. After the polls closed at 7:30 p.m central (8:30 p.m. eastern) the early voting results gave O'Connor more than a 2 to 1 lead, but that differential was anticipated by both sides. Provisional votes remained to be counted. Strong on Crime, Border & Military. Bernie Sanders (I-Vt.) and Alexandria Ocasio-Cortez (D-Bronx/Queens) saw their chosen Michigan Democratic gubernatorial-primary candidate, Abdul El-Sayed, lose.
O'Connor needed Franklin County - which includes the state capital of Columbus - to come out strongly for him in order to topple his Republican rival.
GOP aligned groups sunk more than $5 million into the race, while outside groups backing the Democrat invested more than $1 million.
President Donald Trump campaigned for Balderson, arguing Republicans need to control Congress and casting the midterms as a referendum on himself. At one point in the campaign, Balderson couldn't name a single area of disagreement but since cited differences on tariffs and immigration.
"That this race is too close to call speaks volumes about Danny O'Connor's strength and Republicans' expensive, failed playbook", said Rep. "We are in a tie ball-game", he told supporters at his election night party. Described by campaign operatives as a "Whole Foods" district, the largely suburban region features a far more affluent and educated voter base than the typical Trump stronghold.
Switzerland crash: Up to 20 feared dead as WW2 plane crash
A plane crashed on the Piz Segnas mountain. "We can not yet explain what led to the tragic accident on Piz Segnas", he said. Police spokeswoman Anita Senti told reporters that it was with "sad certainty" that "the 20 people aboard perished".
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.
Also in the race: Native American attorney Sharice Davids and former school teacher Tom Niermann.
O'Connor dominated Balderson on the local airwaves.
In Michigan, three mainstream Democrats in suburban Detroit were among those vying for a chance at retiring Republican Rep. Dave Trott's seat in November.
But political observers said the fact the race was so close in a district that Democrats have not held since Ronald Reagan was president was notable. Two vulnerable Senate Democrats, Missouri's Claire McCaskill, and Michigan's Debbie Stabenow are facing challenges in their states.
The day after Trump's appearance, Ohio Gov. John Kasich, a prominent GOP critic of Trump, said he asked Balderson if he invited Trump at all into the district in the Columbus suburbs - the sort of area where Republicans have lost voters who rebelled against Trump in previous special elections.
Balderson also got a boost from second-term Ohio Gov. John Kasich, a Republican who endorsed him late in the race, even as he sounded an alarm over the Trump-driven tactics, warning that they had alienated suburban women, in particular.