More Californians are bypassing the polling place in favor of voting by mail, changing campaign dynamics but helping to identify the winners and losers early in the night in the first count of ballots. The growth of what is known as “convenience voters” was evident in the June 5 primary, when a whopping 65 percent of Golden State residents made their choices via mail ballot. San Diego County mirrored the statewide trend, also coming in at 65 percent. In adjoining Riverside County, more than 70 percent of voters chose the mail method. Voting by mail greatly increases the number of early voters, requiring campaigns to make sure they reach those people weeks before the official Election Day. “No longer can campaigns count on a last-minute surge through some kind of story or advertising or revelation that could change the election in the last few days,” said Jack Pitney, a widely respected political scientist at Claremont-McKenna College near Los Angeles.