Bernie Sanders speaks to supporters in Riverside, California, Tuesday afternoon, May 24, 2016. Sanders is barnstorming California in an effort to upset Hillary Clinton in the June 7 presidential primary as he struggles to keep his hopes for the Democratic nomination alive.

The primary road ends in California, where the largest share of delegates is at stake. Conventional wisdom gives Sanders little chance of overcoming Clinton's large lead in pledged delegates, but 2016 has not been a good year for conventional wisdom.