And because they are hidden, many of the tax expenditures go to those who need them least, the well connected and established over the vulnerable and the entrepreneurial.

The good news is that change might finally be coming. The Obama administration has always theoretically supported a simpler tax code even while operationally it has often muddied it up. Nonetheless, this week, Treasury Secretary Timothy Geithner unveiled a modest but sensible plan to simplify the corporate tax code. The plan is not perfect. The Obama technocrats love tinkering and complexity. But Geithner’s plan moves us a small step in the right direction and provides a sensible foundation for the big tax negotiations to come.

Mitt Romney has a bigger proposal, which reduces individual rates across the board and closes some loopholes. It’s more comprehensive than the Geithner approach, but it suffers from two weaknesses. First, it’s politics as usual. Romney is specific about the candy — lower tax rates — but vague about the vegetables — what loopholes would have to be closed to pay for them.

Moreover, it’s unimaginative. Republicans are perpetually trying to do what Ronald Reagan did. But top tax rates today aren’t as onerous as they were in 1980, so lowering them won’t produce as many benefits. Imagine if Reagan ran for office promising to recreate the glory days of Thomas Dewey and you get a sense of how much G.O.P. thinking is stuck in the past.

Still, let’s take our good news where we can get it. Attention is shifting to tax expenditures and not just direct spending. It’s becoming clear how gargantuan, opaque and inefficient the U.S. government has become. Maybe before long our political leaders will actually summon the political will to take on the special interests that defend these tax breaks.

This should be the top priority: A tax reform effort that simplifies government frees the economy and focuses social support on those who actually need it. A left-right tax reform alliance to do that would break the political logjam as well as the economic one.