San Francisco Giants President and CEO Larry Baer compared Sacramento’s efforts to build a new arena to the campaign to build Pac Bell Park in San Francisco, telling a collection of businesspeople and government officials that there is “tremendous opportunity” for Sacramento going forward. Baer’s remarks were part of the 2012 State of Downtown address at Memorial Auditorium Tuesday morning, in which Mayor Kevin Johnson, State Senate President Pro-Tem Darrell Steinberg and other officials stressed the “why” of building a downtown entertainment and sports complex. Baer said efforts to build the downtown ballpark in San Francisco were under way as early as the 1960s, with four attempts at u