WHEN I first encountered Ron Wyden in 1974, he was setting up the Oregon outpost of the Gray Panthers, a lobby group founded by the liberal activist Maggie Kuhn with a broad agenda but an emphasis on empowering the elderly. Wyden, who was 25, seemed improbably boyish to be a champion of senior citizens. But he radiated a winning, wonky exuberance. He was clearly bound for a life in politics. He won an insurgent campaign for a House seat in 1980, graduated to the Senate in 1996 — and now, at age 63, has spent almost exactly half his life on Capitol Hill.

If the name rings a bell, it’s probably because Senator Wyden — without really deserving it — has become a bumper sticker in the Republican presidential campaign. Wyden, an Obama Democrat, co-authored a Medicare reform proposal with Paul Ryan last year, a precursor to the Ryan budget plan that Democrats have pilloried as a heartless effort to throw grandma and grandpa off the train. When Romney and Ryan refer to their Medicare thinking as “bipartisan,” as they do ceaselessly, they mean Ron Wyden. In truth, Wyden never subscribed to the most draconian aspects of the Ryan blueprint, but the fact that the Romney-Ryan ticket uses his name as cover has not endeared Wyden to his own party. Charles Pope, the Washington correspondent for Wyden’s hometown paper, The Oregonian, began a thoughtful analysis of the senator’s predicament this way: “Trail blazer or traitor?”

We’ll get back to Medicare in a moment, but let’s linger a bit on what this episode tells us about the decline of the honorable craft of lawmaking.

Back in the day, when Wyden was young and Congress was held in slightly higher esteem, it was common and respectable for lawmakers who disagreed about most things to meet up on a patch of common ground. Ted Kennedy, the iconic liberal, and Orrin Hatch, an uberconservative, often joined forces to expand health care for children or to protect the rights of the disabled. John McCain — an earlier, less cynical version of John McCain — was an aisle-crosser of the first order on issues like immigration. A willingness to forge such alliances used to be taken as evidence that one put the country’s business above party conformity. It let Republicans show they had a heart and Democrats show they could be hardheaded. Nobody embraced this tradition more enthusiastically than Ron Wyden.