Edward L. Glaeser outlines it:
The party, nationally and even locally, has focused on winning suburban and rural votes and has stopped reaching out to city dwellers. The cities-as-foreign-territory approach is bad politics for the Republicans: after all, successful cities like New York and Houston surge with ambitious strivers and entrepreneurs, who should instinctively sympathize with the GOP’s faith in private industry. The Republican move away from the cities is also bad for the cities themselves, which have hugely benefited—and could benefit a lot more—from right-of-center ideas.
One example is traffic:
The congestion can end only when America’s cities stop following what is, in effect, a Soviet-style transportation policy. In the Soviet Union, the government sold eggs and butter at prices far below their market value. The result: long lines and empty shelves. The nominal prices were low, but you couldn’t get your groceries. Today’s cities similarly provide free access to a valuable commodity, city streets. The result: traffic jams, the automotive equivalent of long lines and empty shelves. Until we turn to a market-based solution—following the examples of London and Singapore, where drivers pay for the congestion they create—our cities’ transportation arteries will stay clogged.