Last week I spoke before a very committed group of juniors and seniors taking a college class on sustainable cities. In our discussion I suggested that one approach to improving public transit would be 1) to end all subsidies for fossil fuels, cars and trucks including road building and repair subsidies and 2) to place very heavy taxes on fossil fuels and the use and ownership of roadway vehicles. This I conjectured would make private investment in and ownership of city transit and intercity passenger rail attractive (which is the way it used to be) and could lead to a relatively rapid buildout and improvement of such services. But, I concluded, the first two steps are, of course, politically impossible.

My last remark evoked a spirited rebuttal from a woman in the class. She said, “I’m tired of people in your generation saying that everything we really need to do is politically impossible. All of us here are graduating soon, and we will be moving into positions of responsibility including ones in government. When we’re the generation making the decisions, the things we need to do won’t be politically impossible.” Point taken. I promised in the future to tack on the words “right now” to any declaration that some action seems politically impossible.

With this exchange in mind, as the week unfolded, I began to notice that certain things which only a few months ago seemed “politically impossible” were now be trumpeted as possible and perhaps likely. Who would have guessed a few months ago that the U. S. Senate would be seriously debating whether the country’s largest banks should be broken up into smaller banks? Who would have given such a move even the slightest chance of passing let alone a fighting chance? Even though the proposal was defeated, it garnered 33 votes. It seems doubtful that the issue is dead given the continuing rage against the large banks, and the possibility that another financial panic may result from the sovereign debt crisis in Europe or from a crash in China as its real estate bubble collapses. And, the financial reform bill as a whole which the Republicans and the big banks vowed to stop now seems headed for approval.

I have also begun to think that maybe the Obama administration’s energy and climate legislation which includes an end to some subsidies for fossil fuels might actually pass. Congress has yet to act on it; but the oil spill in the Gulf of Mexico has put the entire fossil fuel industry on the defensive. How quickly things change. Even the sclerotic, corrupt U. S. Congress–made pliable and timid by the monied interests through campaign contributions and the threat of attack ads–seems to have awakened from its long slumber of submission.

When the president first proposed changing the health care system to provide universal coverage, I gave such legislation no chance of passing. I was certain the insurance companies could sink any bill through attack ads, fake public demonstrations, a monstrous media relations disinformation campaign, and direct contributions to key members of Congress. Although I’m not particularly pleased with what did pass, I was completely wrong about whether something could pass. Apparently, it was not “politically impossible” to do so.

Circumstances, strategy, personalities, evolving political alignments and myriad other variables change what is politically possible and impossible from week to week, from month to month and from year to year. But, after being stuck in first gear for a long time, history seems to be on the move. The oil price spike, the financial crisis, a dramatic election that put the first African-American into the Oval Office–something that was previously deemed “politically impossible”–all seem to have shaken even the entrenched U. S. political establishment out of its torpor and made, in some cases, the unthinkable, thinkable and the politically impossible, possible.

If my young student is any indication, there is more to come.