Historically if there is a race up until the convention the front runner stumbles a bit

[book_worm]

Here are the last four democratic primary races where the contest lasted up to the convention and it shows that HRC isn't the only front-runner for the nomination to have some late primary set-backs:

1976--Jimmy Carter won only 7 of the last 15 contests--the rest were split between Jerry Brown, Frank Church, Scoop Jackson and in North Dakota an uncommitted slate won. Carter was nominated on the First Ballot.

1980--Edward Kennedy won 5 of the last 8 primaries (including New Jersey and California--Carter won Ohio). Carter was nominated on the first ballot.

1984--Walter Mondale won only 5 of the last 15 primaries. Gary Hart won 8 & Jesse Jackson 2. Mondale was nominated on the first ballot.

2008--Hillary Clinton won 6 of the last 10 primaries (including Pennsylvania and California). Barack Obama was nominated on the first ballot.

[TwilightZone]

1. Which makes sense

When the outcome looks to be set, supporters of the front-runner naturally relax a bit and aren't as motivated to get out and vote. The general public and the media start looking toward the GE.

Supporters of the other candidates still think there's hope - especially if their candidate is prodding them along - so their turnout doesn't drop as much.