Tried, Tested and no leap of faith needed
200mph rail does indeed take less time than air travel for distances such as LA to San Francisco - as for most travellers the train stations will indeed be closer than airports.
More people live near these stations than near the airports and no security is normally needed to join any of the trains already travelling the 12,000 miles of 200mph rail lines already open across the world. Remember that only a tiny bomb would bring a plane down and kill everybody. They already tried to blow up a French train. Nobody died and it did not even derail. Trains are rather safer. TWO BILLION people have now travelled safely on 200mph rail across France alone now.
Even if the cost does go up, the cost of alternatives would be equally inflated. 200mph rail does normally pay back its construction costs over 30 year periods. Otherwise so much of it would not have been built in the past 30 years in France, Spain, Turkey, Italy, Germany, Britain, Holland, Belgium, Korea, Taiwan, Japan and China.
It works and over the sort of LA to San Francisco distance it typically takes over 80% of the air market (as it now has on routes like Madrid-Seville or London-Paris). On routes like Paris-Brussels, Paris-Lyon, Cologne-Frankfurt rail has taken ALL of the old air market. Airlines gave up flying those routes entirely - as the train was faster than the plane.
Here in England a low cost airline called Ryan Air tried to claim in an advert that their airline was faster, cheaper and more reliable for their London-Brussels route. A judge stopped their campaign as he found that the opposite was true. When YOU TOOK INTO ACCOUNT THE JOURNEY TO THE AIRPORT (from London and Brussels) it was the TRAIN that was faster, cheaper and more reliable.
Since then Road congestion gets worse, fuel costs rise, air congestion gets worse and air security checks take ever longer. Train travel here in Europe has grown through the recession whilst air travel has dropped.
High Speed Rail really can be faster, cheaper and more reliable for California than either air or road travel. Just do not take too long about building it!