COLUMBUS, Ohio, Saturday (AP) - Barack Obama and John McCain, rivals for the White House, squabbled on Friday over terms for a series of face-to-face town hall meetings and each side blamed the other for an inability to reach an accord.

Democrat Obama and Republican McCain, opponents in the November election, also bickered over ways to salvage Social Security, the U.S. government retirement system for seniors that is at risk of going broke in the decades ahead.

The presidential libraries of Democrat Lyndon Johnson and Republican Ronald Reagan offered to host the two candidates at separate town hall meetings. McCain, 71, quickly accepted and accused Obama, 46, of rejecting his offer from two weeks ago to hold 10 face-to-face encounters, one a week, throughout the summer.

McCain campaign manager Rick Davis said in an e-mail the Obama side had instead offered to take part in only one town hall before the Democratic nominating convention in Denver in late August.McCain called on Obama to reconsider and join him in a town hall meeting as early as next week. “His people have responded with a ... very disappointing response,” McCain told reporters in Pemberton, New Jersey.

Obama campaign manager David Plouffe said his candidate had offered to meet McCain five times before Election Day -- in the three presidential campaign debates that normally take place plus a joint town hall on the economy in July and an in-depth debate on foreign policy in August.

“That package of five engagements would have been the most of any presidential campaign in the modern era -- offering a broad range of formats -- and representing a historic commitment to openness and transparency,” Plouffe said.

McCain prefers a town hall format over speeches, during which he has been known to mangle his lines.

Michelle Obama, ends tough stretch with friendly crowd

Barack Obama kisses his wife Michelle Obama, after she introduces him at Oakleaf Village retirement community in Columbus, on Friday

It has been a rough 10 days for Michelle Obama, wife of likely Democratic presidential nominee Barack Obama. Internet rumors claimed there was a videotape of her criticizing ''whitey'' from a church pulpit. A Fox News analyst suggested that her affectionate on-stage knuckle bump with her husband, on the night he locked up the Democratic presidential nomination, might have been a ''terrorist's fist jab.'' Fox also labeled her a ''baby mama,'' a term some use for unwed mothers.

The rumors and innuendo reached the point that Barack Obama's campaign launched a new Web Site this week, fightthesmears.com. The first allegation it denied was the ''whitey'' claim, stating, ''No such tape exists.''

On Friday, Michelle Obama made her first public appearance since these hubbubs arose, and the campaign made sure she had a nice, soft landing.

She introduced her husband to about 40 elderly people at the Oakleaf Village retirement center in Columbus, Ohio. The potential first lady quickly had the roomful of grandparents chuckling and applauding as she managed to praise them along with her husband and their two daughters.