(CNN) -- President Barack Obama and Mitt Romney battled over Medicare and energy policy Tuesday as the November election campaign reached out to battleground states crucial to both sides' chances for victory. In an escalating struggle to seize the advantage on the contentious Medicare issue, the Romney campaign counterpunched with a new ad accusing Obama of cutting more than $700 billion from the government-run health care plan for senior citizens. Romney made the same claim at two Ohio campaign appearances, three days after his selection of House Budget Chairman Paul Ryan brought the issue to the forefront of the campaign spotlight.Romney campaigns in Ohio, calls Biden's Wall Street remark outrageousA new Romney ad takes on President Obama on MedicareObama promotes wind energy in Iowa
At a campaign event Tuesday in Ohio, _ beat the same drum. The president cited a thriving wind energy industry in the state, noting it supports nearly 7,000 _ jobs. "If he knew what you've been doing, he'd know that about 20% of Iowa's electricity now comes from wind, powering our homes and our factories and our businesses in a way that's clean and renewable," Obama said, later calling for a halt to billions of dollars in tax subsidies to oil companies making "huge profits" and instead investing in "the new homegrown energy that's creating jobs here in _." He accused _ of promising to lift regulations on big banks that would "unchain Wall Street," adding: "He is going to put y'all back in chains." An Obama campaign spokeswoman said earlier the president had no problem with _'s statement.