President Obama put a new spin on his attack on Mitt Romney as an "outsourcer," citing a new commentary in a campaign speech today that suggests that his rival's policies will lead to American jobs shifting overseas.

But Obama's attack was greeted with a vigorous defense from Republicans, who argue that some of the president's allies also support changes in the territorial tax system that Romney advocates.

Speaking at a town hall-style meeting in Cincinnati, Obama referenced the analysis by Reed College columnist Kimberly Clausing in Tax Notes that found Romney's support for changes in the territorial tax system would "increase employment in low-tax countries by about 800,000 jobs."

At the heart of the Obama campaign's argument is Romney's support for eliminating U.S. taxes on foreign profits by American companies, which it says encourages U.S. companies to move their operations overseas. Clausing, an expert in international taxation, says the policy shift would lead to hundreds of thousands of jobs being shifted to China, India, Canada and other countries.

"There is a new study out by a non-partisan economist that Gov. Romney's economic plan would in fact create 800,000 jobs," Obama said. "There's only one problem. The jobs wouldn't be in America."

But Republicans fired back that Clausing is hardly non-partisan. The economist has twice contributed to Obama's re-election campaign as well as the Democratic Congressional Committee, the Democratic National Committee, and the presidential campaigns of Democrats John Kerry, Al Gore and Howard Dean.

Further, House Speaker John Boehner's spokesman Brendan Buck noted in an e-mail that the head of the President's Export Council and the Bowles-Simpson Commission both backed changes in the territorial job system.

"A competitive territorial tax system for the United States should broadly follow the practice of our trading partners and should … make the U.S. tax system more competitive," wrote Jim McNerny, head of the Export Council and CEO of Boeing, in a 2010 letter on behalf of private-sector members of the council.

Obama can't get enough of Ohio.

Just two weeks after visiting Ohio during a two-day bus tour, Obama was back in the battleground state to trumpet his call to extend the George W. Bush-era tax cuts for the middle class, while eviscerating Romney as a champion for the wealthy.

After his speech, he took seven questions from members of the audience, including queries about the economy and his favorite Girl Scout cookie.