Vice President Joe Biden campaigns in Ohio; GOP's Paul Ryan to visit

DAYTON, Ohio - Vice President Joe Biden focused his latest campaign visit on the deaths of an ambassador and three more Americans in an attack at the U.S. consulate in Libya, saying there's "no place in the civilized world" for such "senseless murder."

The Democrat opened a rally on Wednesday at Wright State University with a message of mourning for those killed the previous day. He said it's a reminder of the dangers faced by U.S. diplomats abroad.

"Let me be clear: We are resolved to bring to justice their killers," he said.

He added that the United States remains committed to its mission abroad.

"We never have been and we will not be run off. Period," Biden said.

The vice president spoke to hundreds of people at the southwest Ohio school, where Republican then-presidential candidate John McCain introduced Sarah Palin as his running mate in the 2008 race. Biden's audience included comedian Dave Chappelle, who has a home in nearby Yellow Springs.

Biden told the crowd the administration of President Barack Obama is committed to economic growth through a fair tax structure that puts more money into middle-class pockets and encourages companies to keep jobs in the United States.

"We believe what we should be doing is promoting the private sector, not the privileged sector," Biden said.

He said the administration pledges to continue increasing manufacturing jobs in Ohio and again pointed to the rebound in the U.S. auto industry.

Republicans challenged that picture of economic improvement.

"What's clear is that despite Vice President Biden's assertions, Miami Valley families are not better off than they were four years ago," Chris Maloney, a spokesman for GOP presidential candidate Mitt Romney, said in an email.

Romney's running mate, Paul Ryan, also was to appear Wednesday in Ohio. He was headed to an evening rally in Clermont County, east of Cincinnati, as both campaigns continued to give high priority to the swing state.

Romney was in Mansfield earlier this week.

Polls have indicated a tight race with Obama slightly ahead in Ohio, a state considered likely to be crucial to Romney's chances of unseating him.

Obama carried Ohio in 2008 after George W. Bush had won Ohio twice.