ONE of my favorite quotes about the state of U.S. politics was offered a couple years ago by Gerald Seib, a Wall Street Journal columnist, when he observed that “America and its political leaders, after two decades of failing to come together to solve big problems, seem to have lost faith in their ability to do so. A political system that expects failure doesn’t try very hard to produce anything else.” That’s us today — our entire political system is guilty of the “soft bigotry of low expectations” for ourselves.

I raise this now because it strikes me as crazy that one of the obvious solutions to our budget, energy and environmental problems — the one that would be the least painful and have the best long-term impact (a carbon tax) — is off the table. Meanwhile, the solution that is as dumb as the day is long — a budget sequester that slashes spending indiscriminately — is on the table.

Shrinking the tax deduction for charity is on the table. Shrinking Social Security, Medicare and Medicaid for the poor are on the table. But a carbon tax that could close the deficit and clean the air, weaken petro-dictators, strengthen the dollar, drive clean-tech innovation and still leave some money to lower corporate and income taxes is off the table. So the solutions that are lose-lose and divisive are on the table, while the solution that is win-win-win-win-win — and has both liberal and conservative supporters — is off the table.

Writing in this newspaper in support of a carbon tax back in 2007, N. Gregory Mankiw, the Harvard economist, who was a senior adviser to President George W. Bush and to Mitt Romney, argued that “the idea of using taxes to fix problems, rather than merely raise government revenue, has a long history. The British economist Arthur Pigou advocated such corrective taxes to deal with pollution in the early 20th century. In his honor, economics textbooks now call them ‘Pigovian taxes.’ Using a Pigovian tax to address global warming is also an old idea. It was proposed as far back as 1992 by Martin S. Feldstein on the editorial page of The Wall Street Journal. ... Those vying for elected office, however, are reluctant to sign on to this agenda. Their political consultants are no fans of taxes, Pigovian or otherwise. Republican consultants advise using the word ‘tax’ only if followed immediately by the word ‘cut.’ Democratic consultants recommend the word ‘tax’ be followed by ‘on the rich.’ ”