2016 Postmortem
In reply to the discussion: Ok then, Let's spell it out for Hillary "Democrats" [View all]onenote
(43,254 posts)results.
Looking at the last 11 election cycles, the party with higher primary turnout has lost 7 times and only won four.
Even if you take election years in which there is a strong, essentially unopposed incumbent in office (which would generally result in low turnout in the primaries for the incumbent's party), the result is basically a wash:
1976 - Ford was the incumbent, having succeeded Nixon upon the latter's resignation. Reagan mounted a strong primary challenge in what was essentially a two person race, with Ford getting the nod at the convention. On the Democratic side, the race was wide open with an extraordinary number of candidates. The top vote getter, Carter, did only slightly better than Ford in terms of popular vote, but the total Democratic turnout -- pumped up by the fact that Watergate had left the repub brand very badly damaged -- topped 15 million, compared to only around 10 million for the repubs. Carter, of course, won.
1980 - By 1980 Carter had become a fairly unpopular incumbent, with significant primary opposition (from Kennedy). The essentially two man race among the Democrats had higher turnout (17 million plus) than the three man repub race (Reagan, Bush and Anderson with 11.5 million votes) during primary season but Carter lost the GE.
1988 -- No incumbent -- Reagan was a relatively popular outgoing repub president (until just before the election his favorability levels had been fluctuating between 48 and 51 percent for the year). The primary turnout was much higher for Democrats (who had multiple candidates) than for the Repubs (who had basically a two person race between incumbent VP Bush and Dole), but the Democrats lost to Bush by a very large margin.
1992: -- I thought about putting this in category of an incumbent who was essentially unopposed. Bush was a not very popular incumbent president but he faced only moderate primary opposition from Buchanan. The Democrats had much higher primary turnout and won.
2000 -- No incumbent. President Clinton was a moderately popular outgoing Democratic president but carried some baggage. The incumbent VP (Gore) faced one serious primary opponent, Bradley, who was out of the race by March 9. The Republicans had higher turnout (with Bush challenged by McCain, who also was out of the race by March 9). The result: basically a tie (with Gore getting more popular votes despite the Democrats having lower primary turnout).
2008 -- No incumbent. Very unpopular outgoing repub president Bush. Higher primary numbers for Democrats, Democrats win.
In short no predictable pattern of results can be discerned based solely on primary turnout. Out of six races, the party with the higher primary turnout won three times, lost twice and had a split decision (in 2000 despite lower primary turnout the Democrats had more popular votes, but lost the electoral college thanks the Supreme Court). It is obvious that a number of variables influence the results, not just primary turnout. And the 2016 election arguably has the potential to resemble 1988 (with the repub and Democratic positions reversed).
Finally, I'm not sure why some Sanders supporters think that the lower turnout for Democrats means Clinton can't win, but somehow wouldn't mean the same thing for Sanders.