Mitt Romney can now claim victories in Massachusetts, where he was governor, and in Utah, where fellow Mormons supported him.
But rival John McCain has swept a string of delegate-rich primaries in the East and in Illinois, as he tries to take command of the race for the Republican presidential nomination.
Among Democrats, Hillary Rodham Clinton and Barack Obama are trading victories, but in contests where each of them can pick up a sizable number of delegates. Clinton won in her adopted home state of New York, and in Massachusetts, New Jersey, Oklahoma, Tennessee and Arkansas.
Obama won in his home state of Illinois, and in Georgia, Alabama, Delaware, Utah and North Dakota.
McCain captured all 198 delegates at stake in New York, New Jersey, Connecticut and Delaware, while also putting Illinois and Oklahoma in his column.
Former Arkansas governor Mike Huckabee beat rivals McCain and Mitt Romney in West Virginia, Alabama, Georgia, Tennesse and his home state.