By John Whitesides, Political Correspondent
In their hard-fought duel for the Democratic nomination, Obama won nine states and Clinton took six, including some of the biggest at stake on the biggest day of U.S. presidential voting ahead of November's election.
McCain, hoping to knock rivals Mitt Romney and Mike Huckabee out of the race with a strong night, cruised to wins in Connecticut, New Jersey, Delaware, New York, Oklahoma, Illinois and his home state of Arizona.
More than half the total delegates to the Democratic convention in August and about 40 percent of the delegates to the Republican convention in September will be apportioned in Tuesday's voting. The delegates will pick the candidates for the November 4 election.
"This is not going to be decided tonight," Democratic Party Chairman Howard Dean said on MSNBC.
(Writing by David Wiessler; editing by Howard Goller)
