It’s Super Tuesday. That means that people in 15 states (Alabama, Alaska, Arkansas, California, Colorado, Maine, Massachusetts, Minnesota, North Carolina, Oklahoma, Tennessee, Texas, Utah, Vermont and Virginia) and one territory (American Samoa) are going to the polls. Usually, Super Tuesday is one of the biggest dates on the primary calendar — a day when a lot of people across the country make their voices heard. This year is different. There’s no reason to believe that today’s results will alter the seemingly inevitable rematch between President Biden and former President Donald J. Trump. But there are noteworthy primaries in contests that could matter for control of the House and Senate and in important governor races. Today: Amy Walter, the publisher and editor in chief of The Cook Political Report, previews the Super Tuesday races worth watching.