TAMPA, Fla. —
"The first job of government is to keep the American people safe," he said, pledging to do so.
Democrats spent part of their time working to tarnish the Republican brand. They pointed to an ABC News report that said Romney's campaign had held a reception in Tampa Tuesday night aboard a yacht flying the flag of the Cayman Islands.
Romney has been criticized for having investments there by Democrats who say the effect is to reduce his taxes.
In an appearance before University of Virginia students, Obama said he understood Republicans didn't have much nice to say about his tenure in office. He told his listeners the GOP hoped to disparage him so much that they would either vote for Romney or sit out the election.
Romney had already returned to Florida aboard his chartered jet when Senate Republican Mitch McConnell of Kentucky began the convention's daily battering of Obama.
"America is suffering through an economic calamity of truly historic dimensions," he said in excerpts released in advance of his convention appearance.
"Some are calling it the slowest recovery in our nation's entire 236-year history. To call this a recovery is an insult to recoveries." He spoke a few hours after the government reported economic growth for the second quarter was 1.7 percent, sluggish but marginally better than earlier estimated.
Associated Press writers Steve Peoples in Indianapolis, Julie Pace in Charlottesville, Va., Jim Kuhnhenn in Washington and Philip Elliott, Beth Fouhy and Tamara Lush in Tampa contributed to this story
Copyright 2012 The Associated Press.