Republican Josh Mandel focused on jobs, taxes and business regulations Tuesday, as he made the case for his U.S. Senate campaign in a visit to the Dayton Area Chamber of Commerce.

Mandel, currently Ohio’s elected treasurer, is running against Democratic incumbent Sen. Sherrod Brown, for a six-year term. Recent polls have shown that Brown’s lead is down to single digits in some polls, and a dead-heat in others. Brown will address the Dayton Chamber next Tuesday.

Speaking to local business leaders, Mandel said he would be a better friend to business, saying that Brown earned the U.S. Chamber of Commerce’s lowest rating.

“The policies of Sherrod Brown and others in Washington are treating these small-business owners as if they’re guilty until proven innocent,” Mandel said. “We can’t be for job creation and then vilify, with overly burdensome regulations and overly complicated tax code, those men and women who are laying it all on the line to grow these companies.”

Mandel also pushed Chamber members to make Dayton a manufacturing and parts leader in supporting new oil and gas exploration in eastern Ohio.

Brown spokesman Justin Barasky said opposition from the U.S. Chamber is not surprising, calling it a “right-wing organization” and pointing out that the group has spent $5 million in TV ads against Brown so far. Barasky also said Brown has always supported “safe and responsible fracking,” saying Mandel is repeating claims that have already been discredited.

“This is a person who has set, to quote the Washington Post, ‘new frontiers of political dishonesty,’ ” Barasky said. “It’s hard to take anything Josh Mandel says seriously about changing the tone anywhere.”

Mandel called for an overhaul of the nation’s tax code, with lower basic rates, especially for the middle class. He said those low rates should be offset by the elimination of numerous tax breaks that benefit various industries and special interests. He did not specify which breaks should be eliminated, but when asked whether the mortgage interest deduction was one of them, he said no.