CINCINNATI (AP) - Republican Mitt Romney is standing behind Indiana Senate hopeful Richard Mourdock as President Barack Obama's campaign keeps up criticism of Romney's ties to a candidate who said a pregnancy that results from rape is "something God intended."

Romney's campaign has said he disagreed with Mourdock's remark, which came in a debate with opponent Rep. Joe Donnelly late Tuesday. But Romney is standing by his endorsement of Mourdock - and not asking the Indiana state treasurer to take down an ad Romney filmed Monday in support.

The remark thrust a contentious social issue back into the presidential race at an inopportune time for Republicans, less than two weeks before Election Day.