The Obama administration's enthusiasm for high-speed rail is a dispiriting example of government's inability to learn from past mistakes. Since 1971, the federal government has poured almost $35 billion in subsidies into Amtrak with few public benefits. At most, we've gotten negligible reductions -- invisible and statistically insignificant -- in congestion, oil use or greenhouse gases. What's mainly being provided is subsidized transportation for a small sliver of the population. In a country where 140 million people go to work every day, Amtrak has 78,000 daily passengers. A typical trip is subsidized by about $50. Given this, you'd think even...