As with so many things, the answer may lie with history. Consider Mike Huckabee who won the Iowa caucuses in 2008 and Rick Santorum who matched that feat in 2012. In 2016, both men garnered about 1% in the same state’s caucus, and shortly thereafter abandoned their quest for the nomination. To provide a Democratic illustration, in 1968, Gene McCarthy stunned the political world by garnering 42% of the New Hampshire primary vote against a sitting president, whom he helped force from the race as a result. Yet in several subsequent tries for the White House, Clean Gene registered but a blip at the polls.
The lesson is that the American people are enchanted with fresh faces or, stated conversely, grow bored with yesterday’s heroes. If it is true as Andy Warhol famously observed, that everyone gets 15 minutes of fame, Jeb and Hillary are now in their 145th minute and public enthusiasm is growing thin, to say the least. In the 10 elections dating back to 1980, a Bush has been prominently involved in 7 of these contests (George H. W. in 1980, 84, 88 and 1992; Dubya in 2000 and 2004; Jeb in 2016). That’s a staggering 70% of the races stretching over a 40-year span. As for Hillary, a Clinton has run in the races of 1992, 1996, 2008 and 2016, 56% of the campaigns covering the last 25 years.
It might just be that there is nothing wrong with either Hillary or Jeb—except that the public may be experiencing a high degree of Clinton Fatigue and Bush Fatigue. Both candidates may be paying a price for the earlier successes of their spouse, sibling and parent.
Candidates have come back from prior efforts and won the nomination in subsequent election cycles. However the time span between the first aborted effort and the later successful march to the nomination was truncated, either a four or at most an eight-year span. Examples: George H.W. Bush (1980-1988); Bob Dole (1988-1996); Mitt Romney (2008-2012); Hubert Humphrey (1960-1968); and Walter Mondale (1976-1984). In the last fifty years, only two men survived more than eight years in the public consciousness to win their party’s nomination well after their initial effort, Al Gore (1988-2000) and Ronald Reagan (1968-1980). But then again, there may never be another Gipper.