Balderson, who was heavily backed by the White House ahead of the vote, leads Democrat Danny O’Connor by less than a single point but with absentee and provisional ballots yet to be counted.
Such a tight race in a district that gave Trump a 10-point win in 2016 and hasn't voted for a Democrat since the 1980s should set off alarm bells for the GOP ahead of November’s midterm elections.
The Ohio race was one of several elections and primaries taking place across the country Tuesday, with a number of progressives hoping to emulate Alexandria Ocasio-Cortez in toppling more centrist Democrats.
Tuesday’s results mean women have secured a record number of major party nominations for the House, with 182 women so far securing nominations, beating the previous record of 167.
Among the notable victories was Rashida Tlaib, who is on track to become the first Muslim women in Congress this November after winning in Michigan.
Here are the key results:
Ohio 12th Congressional District Special Election:
Troy Balderson — 50.2
Danny O’Connor — 49.3
In the ruby red state of Ohio, this should not have been a contest. Yet with almost all the votes counted, the race, held to replace retiring Rep. Patrick Tiberi, is still too tight to call.
Balderson holds a 0.9 point lead over O'Connor with all early and election day votes counted, but the Ohio secretary of state said early Wednesday there are still several thousand outstanding absentee and provisional ballots left to count — more than Balderson's 1,754-vote lead.
This didn’t stop Trump tweeted that Balderson had won the race, and take credit for his victory after endorsing the Republican. Regardless of who wins, both candidates will have to contest the seat again in November's general election.
Michigan 13th Congressional District Special Election:
Rashida Tlaib — 35
Brenda Jones — 26
Former Michigan state representative Rashida Tlaib took part in two elections Tuesday. The first was to fill the remaining term of Rep. John Conyers, who retired following claims of sexual harassment. She is leading in that race. In the second, for a full term starting in 2019, Tlaib defeated Brenda Jones. The result means Tlaib will become the first Muslim woman elected to Congress as there is no Republican contesting the seat in November.
Kansas Governor Primary Election (Republican):
Jeff Colyer — 40
Kris Kobach — 40
This is another race that is too tight to call, with Trump-backed Secretary of State Kris Kobach and incumbent Gov. Jeff Colyer neck-and-neck. Both sides are awaiting the results from the highly-populated Johnson County, in the Kansas City area. The winner will likely face Democrat state Senator Laura Kelly in November.
Michigan Governor Primary Election (Democrat):
Gretchen Whitmer — 51
Abdul El-Sayed — 31
Despite the last-minute support from Ocasio-Cortez and Sen. Bernie Sanders, Abdul El-Sayed finished behind Gretchen Whitmer in the gubernatorial primary. Ahead of the vote, polls predicted an easy victory for Whitmer, a former state lawmaker. She will now face Republican Bill Schuette in November to replace retiring Republican Governor Rick Snyder.
Michigan U.S. House District 11 (Democrat):
Haley Stevens — 26
Tim Greimel — 21
Suneel Gupta — 21
Fayrouz Saad — 19
Another woman to emerge victorious, Haley Stevens won in Michigan’s 11th district after a tight race in which four candidates all got within 7 points of each other. Stevens' victory was likely helped by a last-minute endorsement from Hillary Clinton.
Kansas 3rd Congressional District (Democrat):
Brent Welder — 36
Sharice Davids — 35
Former Bernie Sanders staffer Brent Welder won a narrow victory over MMA fighter Sharice Davids in a tightly fought contest to take on Republican incumbent Rep. Kevin Yoder. Sanders and Ocasio-Cortez stumped for Welder last month, with the progressive candidate winning despite criticism of his policies, including free college and student loan forgiveness.
St. Louis County Prosecutor Primary (Democrat):
Wesley Bell — 57
Bob McCulloch — 43
In a surprising upset, seven-term incumbent Bob McCulloch was beaten by Wesley Bell, a black Ferguson councilman. McCulloch gained national notoriety for his mishandling of the fatal police shooting of Michael Brown in Ferguson, Missouri, in 2014. Bell was first voted into office in 2015 as a councilman in the midst of the protests of the shooting. “There’s too much divisiveness, too much division in this county, in this region,” Bell said in a video posted on his campaign Facebook page. “We’ve got to start bringing people together.”
Missouri ballot on union dues and right-to-work law:
No — 64
Yes — 35
In a major victory for the labor movement, Missourians voted in a referendum to scrap a Republican right-to-work bill passed last year — a major embarrassment for state GOP lawmakers. Labor groups had stopped the bill coming into effect with a petition to hold Tuesday's ballot. The result could have a nationwide impact, with many states bringing in right-to-work laws that mean workers are entitled to be covered by a union contract without paying union fees.
Cover image: Ohio Democratic congressional candidate Danny O'Connor speaks to supporters at an election-night rally on August 7, 2018 in Westerville, Ohio. (Scott Olson/Getty Images)