Sen. Hillary Clinton and former New York City Mayor Rudy Giuliani hold an edge among candidates in the 2008 presidential race. But an Elon University poll also shows but undecided voters still predominate. Thirty percent of people who said they would vote Democratic supported Clinton... But 24 percent said it was too early to decide and 22 percent didn't know who to support, the poll said. Republicans said it was too early to tell, 31 percent, or they didn't know, 25 percent. Giuliani had 21 percent while Sen. John McCain of Arizona picked up 16 percent and former Gov. Mitt...