The San Antonio Spurs are a major step closer to getting a new downtown home, after voters in Bexar County, Texas approved a plan Tuesday to allow officials to commit up to $311 million in venue taxes to help build a multipurpose arena. County officials said just over 52% of voters supported the measure, which had considerable opposition from some lawmakers and other groups. The Spurs have said they will commit at least $500 million toward construction of an arena, plus cover all overruns —