CHARLOTTE, N.C. – Flinching in the face of economic weakness, President Barack Obama’s top aides refused to say Sunday in the run-up to the Democratic National Convention if Americans are better off than they were four years ago.

Obama campaigned in Colorado and Vice President Joe Biden in Pennsylvania as their senior surrogates sought to deflect discomforting questions and turn them into criticism of Republican challenger Mitt Romney.

“The Romney path would be the wrong path for the middle class, the wrong path for this country,” said David Plouffe, one of Obama’s top White House aides.