CHICAGO — The presidential candidates are criticizing each other in new television commercials aimed at winning working-class voters who could help swing the election, pitting Republican Mitt Romney's wealth against the loss of American jobs to China on President Barack Obama's watch.

As Romney dispatched running mate Paul Ryan to kick off a three-day bus tour in the critical battleground of Ohio, Obama began running an ad in the state trying to use his GOP rival's own words against him.

It's the campaign's first spot using Romney's comments that 47 percent of voters pay no income tax, and believe they are victims and entitled to government assistance. The 30-second ad also points out that Romney paid just 14.1 percent in federal taxes last year on $13.7 million in income and refuses to release his returns before 2010.