BURLINGAME, Calif.—A little over a month before California’s pivotal Republican presidential primary, Donald Trump began his official wooing of party delegates Friday, headlining a kickoff lunch at the state’s annual GOP convention. But Trump’s appearance was nearly derailed by massive protests outside the Hyatt Regency near the San Francisco airport, where the convention is being held. The protests blocked Trump’s motorcade route, forcing the candidate and his Secret Service detail to abandon their vehicles on a nearby highway, jump a barricade wall and cross a ditch to get to the hotel’s back entrance—movements that were captured by television news helicopters.
