For the first time in years, it looks as though California’s primary has a chance to affect the Republican presidential nomination. The primary does not usually offer much sway in the presidential nomination process for two main reasons.
Reason one: the June date. Primaries across the country occur between February and June of the election year, with the majority scheduled in March. This means that by the time California’s June vote rolls around, 88% of the Republican delegates have already gotten behind a candidate.