Republican state Sen. Troy Balderson holds a razor-thin lead over Democrat Danny O'Connor in a special election Tuesday in Ohio's 12th District, with nearly all votes counted. With most of the votes counted, the two candidates traded a lead of just a few hundred votes.
"I've worked in OH presidential and senate races for Republicans and the idea of #oh12 being a close race is sort of like hearing gravity is a regional phenomena", tweeted Republican strategist Stuart Stevens.
The Republican and Democratic primaries for Kansas governor, the Republican primary for Kansas' 2nd Congressional District seat, primaries for local Kansas House of Representatives seats and a Democratic primary for a seat on the Douglas County Commission were among the races that appeared on local ballots.
And in suburban Seattle, three Democrats vied in a jungle primary for the seat held by another retiring Republican, Rep. Dave Reichert.
O'Connor has wiped out most or all of Balderson's lead in opinion polls. That narrow edge came in a district anchored in suburban Columbus, Ohio that President Trump won by 11 percentage points in 2016 and hasn't elected a Democrat in 35 years.
"A month ago this race was flying under the radar, but it has become nationalized and become more of a referendum on Trump, which really generates Democratic enthusiasm", said Patrick Murray, director of the Monmouth University Polling Institute in New Jersey.
Senior Elections Analyst for RealClearPolitics Sean Trende joined Fox News Radio's Guy Benson to give insight into Ohio's special election.More news: Great White Shark Caught Breaching Off Wellfleet
Trump again pushed Balderson in an early morning tweet before voting began. All 435 House seats, 35 of 100 Senate seats and 36 of 50 governors' offices are up for grabs in the November 6 contests.
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.
Strategists in both parties admit that both candidates were fairly mediocre, making the OH race essentially a test of a generic Democrat versus Republican that didn't have as many local vagaries as some other special elections.
Trump took credit for the Republican candidate's performance, calling it "a great victory", even though the contest could be headed to a mandatory recount.
Voters in OH and Kansas joined those in Missouri, Michigan and Washington state.
The Democratic race for governor in MI offered the next test of the electoral power of the party's progressive wing. Gretchen Whitmer, a former state Senate minority leader, is the favorite and millionaire Shri Thanedar has also sought to promote himself as a progressive alternative. And Kobach - who publicly backed Trump's false claim that millions of people voted illegally in 2016 and who advocates a hard-line approach to immigration - could alienate Republican voters in areas like the Kansas City and Wichita suburbs.
Meanwhile, more than 700 miles to the west, Kansas Republicans were fighting among themselves in the battle for governor, where Secretary of State Kris Kobach was trying to unseat Gov. Jeff Colyer. He submitted petitions Monday with more than 10,000 signatures for what could become the most serious independent run for Kansas governor in decades.