DES MOINES, Iowa — The newly shaped Republican presidential ticket is coming under sharp attack from President Barack Obama's re-election team which asserts that challenger Mitt Romney favors his new running mate's controversial plan to overhaul the government's health insurance plan for the elderly and cut trillions of dollars from social programs. Little more than 80 days remain in a campaign dominated by a weak economic recovery and a national jobless rate of 8.3 percent. Polls taken before Romney made Rep. Paul Ryan his vice presidential pick showed Obama with a slender advantage in a contest that will be decided in eight to 10 battleground states. The debate moves across five of these swing states as both campaigns operate at full strength for a second day. Romney spent Tuesday in Ohio on the final day of his multistate bus tour, having dispatched his vice presidential pick Ryan, to court voters and donors in Colorado and Nevada. For all the advantages of having a running mate to share the workload, the Republicans are working through the challenge of planning double the events, coordinating messaging on the road, new security stresses and simply getting to know each other. All the while, Obama and Vice President Joe Biden are linking Romney to Ryan's House Republican budget proposals, which could impact millions of Americans — seniors in particular — if enacted. Obama is holding events in Iowa on the second day of a single-state bus tour, while Biden, who played the role of Obama's attack dog on Monday, is set to campaign in rural southern Virginia. Two days after formally selecting Ryan to complete the Republican ticket, Romney publicly praised his running mate's work as necessary to protect the long-term survival of Medicare, the government-run health insurance program for the elderly. Ryan has “come up with ideas that are very different than the president's,” Romney said in Florida, the state with the highest percentage of residents age 65 and over. “The president's idea for Medicare was to cut it by $700 billion. That's not the right answer. We want to make sure that we preserve and protect Medicare.” Romney did not say so, but the plans Ryan produced in the past two years as chairman of the House Budget Committee retain the $700 billion in Medicare cuts even as they call for the repeal of Obama's health care plan. Romney said there may be differences between his own budget plan and Ryan's, but he refused to detail them. Romney's staff said the former Massachusetts governor favored a plan to restore the $700 billion in cuts. In keeping with tradition as No. 2 on a presidential ticket, Biden embraced the role of attack dog, mocking those who say Ryan's budget plan, adopted only by the Republican-controlled House of Representatives, was a bold attempt to fix the country's fiscal problems. “What's gutsy about giving millionaires and billionaires tax breaks? What's gutsy about gutting Medicaid, Medicare, education?” Biden asked as an enthusiastic crowd of about 900 supporters at the Durham Armory in North Carolina roared in approval. Ohio is likely the most difficult to win of the four must-win states Romney toured by bus — he also visited North Carolina, Virginia and Florida. — AP