Mercury News: It was 139 years ago when railroad baron and future university founder Leland Stanford drove in the Golden Spike at Promontory Summit, Utah, completing the transcontinental railroad and forever changing California. Supporters of a new high-speed rail measure on the Nov. 4 statewide ballot hope voters will perform the electoral equivalent, hammering home a yes vote and reshaping the state’s future again. Proposition 1A would authorize the sale of $9.95 billion in bonds to begin …