Romney campaigns in Florida following weekend VP announcement

St. Augustine, Florida (CNN) -- Fresh off a non-stop weekend of campaigning with his new running mate, Mitt Romney still seemed to be riding high at a free-wheeling rally Monday morning, August 13th in Florida.

The presumptive GOP nominee diverted from his standard stump speech into a host of new material tailored to voters in this prized swing state: on the American space program, the housing crisis that hit Florida particularly hard, and the Medicare program popular with seniors.

"We want to make sure that we preserve and protect Medicare," Romney said, as he praised Paul Ryan, the House budget chairman and new addition to the Republican ticket.

Romney's assertion came as Democrats moved quickly to define Ryan on the national stage as an ultra-conservative who would dismantle the government health care program beloved by seniors. Ryan was the architect of House Republicans' budget plan to address the national deficit, including a proposal to reshape Medicare for citizens under age 55.

"Mitt Romney's not telling the truth about the Medicare savings in the health reform law," said Obama campaign spokeswoman Lis Smith on Monday. "It's unfortunate that Mitt Romney would rather distort the truth than have an honest debate about the devastating impact the Romney-Ryan plan would have on Florida's seniors."

Romney's Monday rally - his first solo appearance since his vice presidential announcement - was closely watched by politicos and the media, after he drew larger-than-usual and very enthusiastic audiences at events with Ryan over the weekend.

Monday morning, the Orlando Sentinel reported Romney canceled a third Florida event due to exhaustion from his busy weekend. Campaign spokesman Kevin Madden pushed back on that report, saying Romney had a "packed schedule and a full day" including meetings with staff.

For his part, Romney offered his audience a full-throated celebration of America, both at the Olympics and in the NASA space program.

"I know there are people around the world who are always critical of America, have something negative to say, say our greatest days are in the past. Baloney. We just won more Olympic medals than any other nation on earth," Romney said.

He continued: "We just landed on Mars and took a good look at what's going on there. And, I know the Chinese are planning on going to the moon, and I hope they have a good experience doing that, and I hope they stop in and take a look at our flag that was put there 43 years ago!"

In an apparent rebuke to the event's organizers, Romney made mention of the lines of supporters who listened from outside the security barricades at Flagler College.

"I understand there are even more people outside those barricades than inside here, so the people way out there, thank you for coming today," he said. "Looks like we just didn't have enough of those mags to get everybody in in time."

Romney closed his event with a story about a Boy Scout troop leader who arranged to have their troop's American flag aboard the Challenger space shuttle, which exploded on takeoff in a deadly tragedy.

NASA later found the flag in perfect condition, Romney said.

"I looked over at that flag and I put my hand on it and pulled it out -- it was like electricity was running through my arm as I was holding onto that flag," Romney said. "You see, to me it represented the people who strive in this nation. The people who reach out, who make discoveries that enhance America. It's the nature of who we are."