Possible 50% pullback leading up to the election

Election years in which the outgoing president is finishing up his 2nd term has had a pretty substantial effect in
the months leading up to the election. In 1987 the market tanked before Reagan left office in 1988 , 2008 when Bush II was leaving office , and it looks like it can happen again when Obama rides off into the sunset.
I believe uncertainty drives the bearish movement .Ultimately the markets all recovered once we knew in which lobbyists will be rewarded..