Barack Obama and Hillary Clinton are looking for votes in Mississippi tomorrow, but last week's flap over the North American Free Trade Agreement is still on the radar screen. US Ambassador David Wilkins complained that the Canadian government had interfered with the US political process. During a Clinton-Obama debate in Ohio, both promised publicly to pressure for renegotiation of NAFTA, but Ohio voters heard only about Obama. Canada TV then reported that an Obama aide had privately reassured Canadian officials not to worry, that it was all political rhetoric in a state where NAFTA is blamed for a loss of jobs. The Clinton campaign accused Obama of dishonesty, and the issue contributed to his loss in Ohio. Meantime, as Clinton escalates her attacks, Obama is beginning to respond in kind. Are they handing John McCain issues to use in November? Will their ongoing battle make it harder for him to get the attention he needs to rally Republican skeptics?