Mitt Romney has won the South Dakota Republican presidential primary, adding to a delegate total that already exceeds the number needed to win the nomination.
Romney also won the New Jersey presidential primary on Tuesday. Presidential primaries were also held in New Mexico, Montana and California.
A total of 264 delegates were at stake in Tuesday's contests, and Romney has a chance to win them all. Romney has 1,266 delegates. He needs 1,144 to win the nomination.
With the primary season winding down, Romney is already in general election mode. He will take on Democrat Barack Obama in the fall.
After Tuesday, only one Republican presidential primary remains, in Utah on June 26.