More from the Washington Post story:

Udall helped write several of the most far-reaching pieces of legislation, including the Wilderness Act of 1964, which protects millions of acres from logging, mining and other development. "I never lost an argument with the budget people under either Kennedy or Johnson. If you had a new national park or a new policy on wilderness or something on wild rivers ... they'd say, `Go ahead. It's a good idea,'" Udall once said in an interview.

Udall also famously predicted the energy crisis in a 1972 Atlantic Monthly Article entitled "Too Many Cars, Too Little Oil. In part, he wrote words that ring eerily true today:

In my view, it is unfortunate that most oilmen are willing to take a final ride with the boomer geologists. They apparently believe that the country should base its energy policies on the bet that another round of big oil strikes is in the offing, that an acceptable oil shale technology can be developed overnight, or that last-resort foreign imports can bail us out.

On a personal Stewart and Mo Udall were legendary characters in Arizona politics (where I grew up). To me, their lives are proof that true progressives can indeed win elections in the west.