Plain Dealer – For someone who aggressively markets himself as a spit-and-polish Marine, Republican Senate hopeful Josh Mandel surely seems to have a powerful urge to wallow in the mud of politics.

Two years ago, in a race for state treasurer that he would have been hard-pressed to lose, Mandel nevertheless resorted to a despicable television ad that suggested incumbent Democrat Kevin Boyce, an African-American Christian, was a Muslim who did his hiring in a mosque.

Almost as soon as he won the treasurer’s job, Mandel set his sights on Sen. Sherrod Brown.

His challenge has been buoyed by more than $8 million worth of negative ads produced and purchased by outside groups that despise Brown’s liberal voting record. Mandel cannot control the messages in those spots or their grainy images. But presumably he can control what comes out of his own mouth.

And yet there has been a growing list of statements that The Plain Dealer’s PolitiFact Ohio team has identified as false. Mandel has, rather astoundingly, refused even to offer evidence supporting some of his own allegations.