McCain won 601 delegates to 200 for Romney and 147 for former Arkansas Gov. Mike Huckabee in incomplete results. A total of 1,023 delegates were up for grabs in 21 states.
Overall, McCain led with 703 delegates, to 293 for Romney and 190 for Huckabee. It takes 1,191 to win the nomination at this summer's convention in St. Paul, Minn.
Clinton led with 763 Super Tuesday delegates to Obama's 731. In Missouri, the race was so close the two candidates split the state's 72 delegates evenly.
A total of 1,681 delegates were at stake in 22 states and American Samoa.
Overall, Clinton has 1,024 delegates, to 933 for Obama with 2,025 delegates required to claim the nomination in Denver at this summer's convention.
The AP tracks the delegate races by projecting the number of national convention delegates won by candidates in each presidential primary or caucus, based on state and national party rules, and by interviewing unpledged delegates to obtain their preferences.
In some states, like Iowa and Nevada, local precinct caucuses are the first stage in the allocation process. The AP uses preferences expressed in those caucuses to project the number of national convention delegates each candidate will have when they are chosen at county, congressional district or state conventions.
