VIRGINIA BEACH, Va. — President Barack Obama pledged to create many more jobs and “make the middle class secure again” in a campaign-closing appeal on Thursday — more than five weeks before Election Day — to voters already casting ballots in large numbers.

Republican Mitt Romney, focusing on threats beyond American shores, accused the commander in chief of backing dangerous cuts in defense spending.

“The idea of cutting our military is unthinkable and devastating. And when I become president we will not,” declared the challenger, struggling to reverse a slide in opinion polls.

Romney and Obama campaigned a few hundred miles apart in Virginia, 40 days before their long race ends. They’ll be in much closer quarters next Wednesday in Denver — for the first of three presidential debates on the campaign calendar and perhaps the challenger’s best remaining chance to change the trajectory of the campaign.

In a race where the economy is the dominant issue, there was a fresh sign of national weakness as the Commerce Department lowered its earlier estimate of tepid growth last spring. Romney and his allies seized on the news as evidence that Obama’s policies aren’t working.