Knowing when he was licked, Poulson last week conceded a scant three hours after the polls closed. Yorty's triumph changed a lot of California political equations. As mayor of Los Angeles, Sam Yorty's influence would have to be reckoned with. But how would he use that in fluence? Would he support Richard Nixon if Nixon were to run for Governor next year against Pat Brown? Or might he try to unseat Brown himself? Nobody knew, least of all Yorty. But one thing is certain: in one way or another. Mayor Sam Yorty will be in the thick of California's political fighting for quite a while.