Hillary Rodham Clinton has accused Democratic presidential rival Barack Obama of political plagiarism in their latest debate in Texas.
Clinton said Obama represented "change you can Xerox." The line drew some boos.
Obama says the disputed words were given to him by his friend and national co-chairman and that the accusation is part of "the silly season."
The 90-minute debate was the next to last before the March 4th primaries in Texas and Ohio and was mostly civil.
In a university auditorium in the heart of Texas, Clinton and Obama agreed that high-tech surveillance measures along the border are preferable to construction of a fence to curtail illegal immigration.
But they sparred frequently about health care. Clinton repeated her charge that Obama's plan would leave 15 million Americans uncovered. Obama accused the former first lady of mishandling the issue by working in secrecy when her husband was in the White House.