It's called Super Tuesday because 11 states (12 for the GOP) hold their nominating contests that day. It's also called the SEC primary because seven of the 11 states are in the South.
With so many states voting, the stakes are high. In a three-person Democratic field, a clear winner could emerge. Even if a winner isn't clear after these states vote on the Republican side, the field is very likely to become smaller as candidates could start dropping out.
