Going all the way back to Kennedy's race in 1960, eight of the 12 presidential contests have yielded a winner who won less than 51% of the popular vote. The only exceptions, in which a candidate assembled a substantial majority, involved three popular incumbents (Lyndon Johnson in '64, Nixon in '72 and Reagan in '84) running for re-election against feeble opponents, and one sitting vice president (George H.W. Bush) who ran as the candidate for "Reagan's third term" and managed to gather 54%.
All other presidential victories produced either minority presidents (Kennedy in '60, Nixon in '68, Clinton in both his races, Bush in 2000) or barely cleared the bar of 50% (Carter in '76, Reagan in '80, Bush in 2004).
These results should stand as definitive rebuttal to cherished myths that continue to bedevil both conservatives and liberals. For decades, right-leaning activists have cherished the notion of a "silent majority," a long-suffering mass of quiet but committed traditionalists who wait only for a "true conservative" Prince Charming to awaken the sleeping giant with a kiss. Some true believers maintain stubborn faith in this much-loved legend of a right-wing consensus ready for arousal by a leader whose voice speaks forcefully enough — a phantom majority that never instantly materialized for Reagan himself let alone Reagan-wannabes such as Pat Buchanan or Mitt Romney.
On the left, ideologues and activists nurture a mirror-image faith in the "idealism" and "radicalism" of the American people, if only the right messianic figure managed to mobilize our long-buried lust for change. This notion of a blocked and sublimated passion for "systemic change" helps explain the huge emotional investment in the three Kennedy brothers to whom their followers imputed near superhuman powers: Despite the fact that Jack was actually a moderate-to-conservative president, Bobby was facing an uphill battle for the Democratic nomination when he was assassinated in '68; Teddy, in his one bid for the White House in 1980, mobilized almost no one and made scant progress even against the hapless Carter. The "movement for change" of Democratic dreams failed to materialize not because of personal deficiencies in any Kennedy or Clinton (or McGovern, Mondale, Dukakis or Gore), but because liberal ideology has never attracted anything near a majority of the populace.
These failures and frustrations on both sides suggest that we most likely will witness another breathlessly close race in 2008 — especially with no sitting president or vice president in the race and scant prospect of a major third-party spoiler. Regardless of Democratic enchantment with Obama, history indicates that even the most electrifying and barrier-busting campaigners will still hover around 50% of the popular vote of a durably divided electorate.
The record also suggests that whatever the Republican criticisms of McCain, he won't fall far below 50% of the public that reliably leans toward his party. In other words, as present polls predict, we'll get another seesaw battle, in which either candidate can tip the result with minor mistakes or unexpected cunning, as they struggle through one more ferocious fight within the narrow confines of this half-century-old presidential deadlock.