CHARLOTTE, N.C. – Democrats ridiculed Republican Mitt Romney as a millionaire candidate for president who "quite simply doesn't get it" and worse on Tuesday, opening night of a national convention aimed at propelling Barack Obama to re-election despite high unemployment and national economic distress.

Obama "knows better than anyone there's more hard work to do" to fix the sputtering economy, said San Antonio Mayor Julian Castro, the convention keynote speaker, sharing the prime-time spotlight with first lady Michelle Obama.

Delegates cheered as a parade of speakers extolled Obama's support for abortion rights and gay marriage, for consumer protections enacted under his signature health care law and for the auto industry bailout he won from Congress in his first year in office.