Most Democratic primaries in 2018 have focused on bread-and-butter progressive issues like healthcare, education and gun control. In Ohio’s gubernatorial primary, however, domestic policy has increasingly been overshadowed by an unexpected figure: Syria’s President Bashar al-Assad.

Syria took center stage last week, after the two-time presidential candidate Dennis Kucinich revealed in an amended filing with the state ethics board that he had received $20,000 for a paid speech to a pro-Assad group in London.

The former congressman has long been hesitant to condemn the Syrian dictator and has travelled to Damascus to meet him on several occasions, including for an interview for Fox News where Kucinich once served as a contributor. Kucinich’s idiosyncratic foreign policy views have earned him a seat on the advisory board of the Ron Paul Institute.

The candidate once interviewed Bashar al-Assad for Fox News. Photograph: Sana/Handout EPA

Only days before his amended disclosure, the editorial board of the Cleveland Plain Dealer endorsed Kucinich, but cautioned “he must never again make nice with Syrian butcher Bashar Assad”.

Andy Juniewicz, a spokesman for Kucinich, said that the candidate’s position on Syria was “not an issue in Cleveland”, adding that “most people don’t want to be engaged in foreign wars and it’s hard to see advocating peace being negative”.

But Kucinich’s main opponent and the current frontrunner, Richard Cordray, who is the former head of the Consumer Financial Protection Bureau (CFPB), has used Syria as a sledgehammer.

Last week, his campaign hosted a conference call with the former Democratic governor Ted Strickland, who previously served in Congress alongside Kucinich. “For years Dennis Kucinich has been an outspoken defender of the Assad regime in Syria even as they’ve killed countless people and used chemical weapons against civilians,” said Strickland.

“On the campaign trail Dennis has refused to condemn Assad … What we now know goes further. Dennis wasn’t just defending Assad out of conviction, he was also being paid by a group that has been a vocal cheerleader for this murderous dictator.”

Cordray spent six years leading the CFPB, the consumer finance watchdog first conceived by Elizabeth Warren, is a comparatively conventional politician. He is a former supreme court clerk who previously served as Ohio’s attorney general and treasurer. Warren has endorsed his campaign and stumped with him and Cordray’s first television ad highlighted copious praise from Barack Obama.

Kucinich has attacked Cordray for his past support for gun rights. In a statement after Strickland’s conference call, the candidate said: “Cordray will do anything to change the subject from his NRA ‘A’ rating and his support for assault weapons on the streets of America.”

Richard Cordray, who is running against Dennis Kucinich, speaks in Cincinnati. Photograph: John Minchillo/AP

Kucinich also lashed out at Strickland for participating in “unfounded and inflammatory” attacks that “grossly misportrayed” his visits to the Middle East.

Democratic observers unaffiliated with the race said while Assad was probably not a voting issue in Ohio, it did add to a broader narrative of Kucinich being an “unreliable Democrat”.

One well-connected state Democrat said “if [Kucinich] was making any progress in getting out of the box of being a little too quirky and a little too fringe this erased a lot of it.”

Kyle Kondik, the managing editor of the nonpartisan election website Sabato’s Crystal Ball and author of a book on Ohio politics, cautioned that not only is Kucinich better known than Cordray in the state but that his attacks on guns “seem like a more fruitful and topical line of attack than Syria does”.