McCain Grilling For A Running Mate?

John McCain opened up his Arizona home Sunday to a select list of Republican VIPs, igniting speculation about who he'll choose to join him on the GOP presidential ticket, reports CBS News correspondent Priya David.

Despite the overt gesture, those close to the presumptive nominee downplayed the gathering.

"This was purely social," Sen. Lindsey Graham, a South Carolina Republican and close friend of McCain who attended the barbeque told Face The Nation host Bob Schieffer. "If you know anything about John McCain, he is like a kid at Christmas when it comes to showing off his ranch up here."

Also among the guests: McCain's one-time rival for the Republican nomination, former Massachusetts Gov. Mitt Romney; the popular governor of swing-state Florida, Charlie Crist; and Louisiana's new governor, Bobby Jindal.

All are younger than McCain, with Jindal, at 36, the youngest of the three.

"He wants to start looking at people, vetting some of his prospects," Politico.com's Jonathan Martin told CBS News. "There's no more important decision for these candidates in the next few months than picking somebody for their ticket who's not gonna be a problem."

Just as important for McCain is choosing a running mate who can offset what's being seen as one of his problems - his age.

McCain will celebrate his 72nd birthday this August, making him, if elected, the oldest person ever to win the Oval Office.

During a Fox News debate in New Hampshire, the veteran of both the Vietnam War and the U.S. Senate made no attempt to sugar-coat his seniority, proclaiming: "I am older than dirt and got more scars than Frankenstein."

McCain's not the first candidate to try to diffuse the issue with humor, reports David.

In 1984, 73-year-old Ronald Reagan, running for re-election, spun age in his favor. "I am not going to exploit, for political purposes, my opponent's youth and inexperience," he said. Reagan won. But, in 1996, Bob Dole had a harder time at 73, losing to Bill Clinton.

Polls show age remains a significant hurdle for McCain.

"We find about one-in-four saying that John McCain is too old, and then when we tell people how old he actually is, that number goes to almost a third of voters," Andrew Kohut of the Pew Research Center tells CBS News.

A cancer survivor and former prisoner of war, McCain released his medical records Friday, showing no significant health problems.

"His doctors have given him a clean bill of health," Democratic rival Barack Obama said. "I don't think it should be an issue in the campaign."

David reports that Obama, a 46-year-old senator from Illinois who gave up smoking just last year, has not released his medical records, and his campaign says he won't - until he's named the Democratic nominee.