VERNON HILLS, IL - Mitt Romney's wife says now is the time for Republicans to unite behind one presidential nominee.

Ann Romney stood at her husband's side last night at a rally in suburban Chicago and offered the campaign's most aggressive plea yet for Republicans to end their extended nomination fight. The comments came moments after Mitt Romney announced he had won all 20 of Puerto Rico's delegates in the island's primary Sunday.

Ann Romney says it's time for the GOP to come together behind one nominee so it can focus on defeating President Barack Obama in the fall.

The Romney campaign hopes Illinois will prove to be a knockout punch against rival Rick Santorum on Tuesday. While some conservatives don't like Romney, he has accumulated more delegates than all his competitors combined.