Mitt Romney has added the Alaska caucuses after he squeezed out a win in the pivotal Ohio primary and captured four other states in the race for the Republican presidential nomination.
The final result means that Ron Paul, who had hoped for an Alaska win, has finished the 10-state series without a single victory.
Mr Romney had to share the Super Tuesday spotlight with a resurgent Rick Santorum.
Mr Romney scored a home-state win in Massachusetts to go with primary victories in Vermont and in Virginia – where neither Mr Santorum nor Newt Gingrich was on the ballot. He also triumphed in the Idaho caucuses.
Mr Santorum countered by winning primaries in Oklahoma and Tennessee and the North Dakota caucuses. Mr Gingrich won his home state of Georgia.
A total of 10 states were voting on Super Tuesday.
More than 400 delegates are at stake on the busiest day by far of the race to pick an opponent to President Barack Obama in the November election.