Megan explains it all.

It’s just a stupid gimmick that will do nothing to make most people better off.

While I don’t like any taxes, I see the gas tax as a better way to raise money for government highway construction than others, because the costs are borne by the beneficiaries.

But, this proposal doesn’t do any good. Good would be to reduce spending.

It’s hard (impossible) to believe that Clinton and McCain don’t know this (or have advisors who know this). It’s just further evidence that politicians care less about the truth than about what will help them get elected. They’d much rather cause further damage and cater to the mistaken biases of voters, than advocate genuine improvements.

Obama may be against this particular example, but he’s got plenty of his own.