HIGH POINT, N.C. >> In Paul Ryan’s high-energy debut as Republican vice presidential candidate, Mitt Romney’s campaign made one thing clear: Romney’s ideas rule, not his running mate’s.

Romney put gentle but unmistakable distance between his agenda and Ryan’s hot-potato budget proposals today as the new team soaked up excitement from partisans in North Carolina and Ryan’s home state of Wisconsin. But Democrats weren’t about to let them off that hook.

President Barack Obama, attending campaign fundraisers today in Chicago, tagged Ryan as the “ideological leader” of the Republican Party.

“He is a decent man, he is a family man, he is an articulate spokesman for Gov. Romney’s vision but it is a vision that I fundamentally disagree with,” Obama said in his first public comments about Ryan’s selection.

Earlier, Obama’s senior campaign adviser David Axelrod deemed Ryan’s budget “the Ryan-Romney plan” and cast the new addition to the Republican ticket as a choice “meant to thrill the most strident voices in the Republican Party, but it’s one that should trouble everybody else — the middle class, seniors, students.”

Romney walked a careful line as he campaigned with Ryan by his side in North Carolina. Romney singled out Ryan’s work “to make sure we can save Medicare.” But the presidential candidate never said whether he embraced that plan himself. During the Republican primary, Romney had called Ryan’s budget a “bold and exciting effort” that was “very much needed.”

Ryan proposed to reshape the long-standing entitlement by setting up a voucher-like system to let future retirees shop for private health coverage or choose the traditional program — a plan that independent budget analysts say would probably mean smaller increases in benefits than current law would provide.

Romney and Ryan, in their first joint television interview today, were clearly mindful that some of Ryan’s proposals don’t sit well with key constituencies, among them seniors in critical states like Florida and Ohio. Each man sought to reassure older voters they wouldn’t take away their benefits, with Ryan saying his mother was “a Medicare senior in Florida” and Romney vowing there would be “no changes” for seniors currently counting on the popular federal program.

“In America, the nature of this country has been giving people more freedom, more choices,” Romney said in an interview with CBS’ “60 Minutes.” “That’s how we make Medicare work down the road.”

Romney aides, echoing talking points they circulated to party leaders and operatives, praised Ryan’s budget work, but sought to draw a distinction between his ideas and Romney’s.

“Gov. Romney is at the top of the ticket,” Romney spokesman Kevin Madden told reporters Sunday. “And Gov. Romney’s vision for the country is something that Congressman Ryan supports,”

Obama’s campaign had already been trying to tie Romney to Ryan’s tough budget blueprint even before the Wisconsin congressman emerged as a contender for the GOP ticket. Democrats believe seniors, those nearing retirement and middle-income voters will view Ryan’s long-term budget plan remaking Medicare and cutting trillions in federal spending as a threat to their financial security.

Campaign officials were readying state-specific strategies aimed at seniors in Florida and Ohio, and also planned to court young people and military service members who they believe will be turned off by other elements of Ryan’s proposed budget cuts.

As chairman of the House Budget Committee, Ryan is the primary author of conservative tax and spending proposals that the tea party-infused Republican majority approved over vigorous Democratic opposition in 2011 and again in 2012.

They envision transforming Medicare into a program in which future seniors would receive government checks that they could use to purchase health insurance. Under the current program, the government directly pays doctors, hospitals and other health care providers.

Ryan and other supporters say the change is needed to prevent the program from financial calamity. Critics argue it would impose ever-increasing costs on seniors.