Objecting to the media's impatience to see the race conclude, CNN's Paul Begala pointed out, "Bill Clinton locked up the nomination on June 2nd, in 1992." Bill Clinton himself has been using the same factoid, so Jake Tapper looked into it a few weeks ago:
That is literally true. Bill Clinton did not secure enough delegates through the primary and caucus process until the California primary, June 2, 1992. But it is not politically true. Bill Clinton had sewn up the nomination long before then. Months before then. ... it was truly over about five or six weeks after the New Hampshire primary.
This year's New Hampshire primary was 15 weeks ago.