Brown, for example, is primarily driven between campaign stops. U.S. Sen. Rob Portman, a Republican who won re-election in 2016, crisscrossed the state primarily via bus. Portman’s Democratic opponent that year, former Gov. Ted Strickland, largely stuck to ground transportation.

But Renacci has opted to fly in aircraft piloted by Ksiezyk to make appearances in Cincinnati, Toledo and Lima, according to a review of the plane’s flight records from the website FlightAware. Matching that data with information from Renacci’s campaign Twitter account shows the majority of flights by the plane this year correspond with Renacci’s campaign schedule.

On Tuesday, for example, Ksiezyk’s plane flew down to Warren County, apparently to pick up Renacci — whose Twitter feed reflected a day’s worth of campaigning in southwestern Ohio — and to fly him home just after 7:30 p.m.

A spokesman for Renacci refused to answer questions about the candidate’s relationship with Ksiezyk and his decision to take a plane across the state. Among the questions she declined to answer was whether the two had ever had a business relationship — Renacci says he has started about 60 companies — and whether Ksiezyk flew Renacci to campaign events during his short-lived bid for governor.

Instead, spokeswoman Leslie Shedd brought up Brown’s 1987 divorce from his first wife and records from that divorce indicating that Brown’s ex-wife had sought a restraining order against him.

“After trashing whistleblowers for speaking out against Sherrod Brown’s multiple acts of domestic abuse and after shamelessly dismissing multiple sworn affidavits detailing that abuse, The Dispatch has sadly hit a new low by publicly shaming a private citizen and Renacci campaign volunteer while giving a pass to Senator Sherrod Brown on his record of domestic violence,” she said.

Outside the House chamber Wednesday, Renacci also was asked about his decision to travel by plane, whether he had any sort of business relationship with Ksiezyk, and whether Ksiezyk flew him during his gubernatorial bid. He repeatedly declined to answer, saying, “You already have my comment on that.”

Ksiezyk did not respond to three emails seeking comment. Five phone numbers associated with him either were disconnected or resulted in messages being left that were not returned, including phone numbers for the two bars he owns.

Erin Chlopak, a campaign-finance expert with the Campaign Legal Center, said that although laws were amended several years ago to bar House candidates from traveling in private planes, that ban does not apply to Senate candidates.

But it has been an issue for other candidates in this election cycle, causing headaches for Democratic Sen. Claire McCaskill of Missouri early in the summer when it was disclosed that she had taken a private plane for part of what was billed as an RV tour. Republicans jumped on that admission, with National Republican Senatorial Committee spokesman Bob Salera telling Politico that McCaskill was “too much of an elitist to even stick to a three-day RV tour without hopping on her private plane.”

Chlopak said Senate candidates are permitted to use noncommercial planes only if they pay the equivalent rate. According to FlightAware records matched with Renacci’s campaign Twitter account, between January and June of this year, Renacci appears to have used the private plane for events 13 times, including round trips from Wadsworth to Cincinnati, Toledo, Piqua and Dayton.

During that period, Renacci for Senate reimbursed Ksiezyk for his in-kind donations of flights three times: $1,066 on March 31, 2018; $500 on June 30; and $967, also on June 30. His next Senate report is due Oct. 15 and will cover the period between June 30 and Sept. 30.

“Where this would get sticky is if you were getting the service for free or at some extensive discount,” said Dave Levinthal of the Center for Public Integrity.

The cheapest round-trip ticket from Cincinnati to Cleveland booked a month in advance costs around $300, according to a review of the travel website Travelocity. For four days in advance, the cheapest flight is about $700, according to the site.

It’s less clear whether Ksiezyk flew Renacci during his short-lived gubernatorial bid.

Records from Ksiezyk’s aircraft indicate that it flew to destinations such as Zanesville, Cincinnati, Hamilton and Dayton throughout the summer of 2017, when Renacci was campaigning for governor. But those flights could not be matched to campaign events. Renacci recorded no contributions from nor expenditures to Ksiezyk in campaign-finance reports filed with the Ohio secretary of state.

Ksiezyk owns two adult entertainment bars in Cleveland: Bug-A-Boos, also known as Johnny’s Tramell’s, and Peek-A-Boos, also known as Elias Brothers Showbar-Lounge. According to the Ohio Division of Liquor Control, he has had a liquor license for the former since 1989, and for the latter since 1981. A bar employee reached by phone confirmed that both bars are still open.

Bug-a-Boos was the site of a May 2016 shooting in which one man was shot to death in the parking lot by another man whom police believe had been escorted out of the bar by bouncers.

Peek-a-Boos, meanwhile, was the source of a running battle between Ksiezyk and the Cleveland Board of Zoning Appeals in the early 2000s over whether it was legal for Ksiezyk to operate a topless restaurant.

In 2002, Ksiezyk sued the city to appeal a zoning decision that barred him from using his property at 3129 W. 25th St. as an adult cabaret. The property was known as Peek-A-Boos and, according to court documents, featured “sophisticated, female topless-dancing performances.” Between 1978 and 1981, it was cited three times for topless dancing under a liquor law at the time that barred topless dancing.

But the court case in 2002 was on whether the bar could be grandfathered in as a topless bar under prior laws. The Board of Zoning Appeals found that was not the case. More recently, Ksiezyk has petitioned the zoning board over an expansion of the Peek-A-Boos site.

Columbus Dispatch library director Julie Fulton provided research for this story.