Just how ‘super’ is this year’s Super Tuesday, anyway?

March 3 is “Super Tuesday” on this year’s Democratic presidential nominating calendar – the biggest single day in both number of elections and the total number of delegates at stake. All told, 1,357 delegates, or about 34% of all pledged delegates to this summer’s Democratic National Convention, will be chosen in 14 state primaries and one territorial caucus (American Samoa). And a weeklong “global primary” for overseas Democratic voters also starts March 3, with 13 delegates at stake.

While clearly significant, this year’s Super Tuesday is by no means the...