It would require elevated tracks in many areas, defacing what little scenery we have left. Further, it would be so expensive to operate, much less build, that a hefty tax increase of some sort would be necessary to help retire the huge bond debt. Also, it would take at least 10 years of almost continuous construction. There are few examples of rail transit being successful in the United States. A car is like an extra appendage.
Lower taxes are also a permanent topic for discussion.
Government can't, it seems, be cut to accommodate lost revenue. When our excise tax was hidden in the price of goods we bought, everyone assumed business was paying it, not their customers. Then when it became legal to add it to your grocery and doctor bills, moves were begun to get it reduced or replaced. Consumers still don't know that every single cost of doing business is contained in the price of goods and services. Like the cost of every rule and regulation imposed by government.