Charles T. Munger Jr. isn't your run-of-the-mill Republican donor. The wealthy Stanford physicist is gaining prominence in a state Republican Party now regularly in search of money needed to win in blue California. But Munger's involvement in the state GOP goes beyond writing checks. His influence will be on display this weekend as California Republicans gather in Los Angeles for their fall convention and begin discussing a Munger-inspired platform that downplays traditional GOP positions on gun rights, abortion and same-sex marriage. The bow tie-wearing Republican has spent recent months shepherding a behind-the-scenes effort to adopt a more moderate California Republican...