Slowly but surely, he turned his thumb down in front of the Senate leader. With this determined gesture, in a moment loaded with expectation, veteran Republican Sen. John McCain dealt the deathblow to President Donald Trump's ambition to repeal Barack Obama's health care reform, which granted medical coverage to millions of people in the United States.

McCain, who is 80 years old and the victim of an aggressive brain tumor, returned to the U.S. Senate this week to give a lesson: a life lesson, a moral lesson and a lesson of passion for politics, at a time when all of Washington's newcomers are rolling around in the mud of vulgar spectacles and wars more befitting Wall Street's sharks than the White House.

The five-time Arizona senator returned to the Senate chamber with visible wounds left by his disease: a scar over his left eyebrow—where, recently, a blood clot was removed—and a visible bruise on his face. Sick, but smiling and strongly determined to defend his convictions, even if they clash with his party's orthodoxy.

Tribalism and Entrenchment

In these strange times of political tribalism and entrenchment, his speech tastes like glory. “Merely preventing your political opponents from doing what they want isn't the most inspiring work. There's great satisfaction in respecting our differences, but without letting them prevent agreements,” said the elderly legislator, who has said he will remain in the Senate as long as he can continue doing the “most important job” of his life.

After defeating the repeal of Obama's health care reform with his thumb, McCain has been turned into the Democrats’ new hero. This is the biggest legislative defeat Trump has faced since becoming president. It is also the most bitter, because the blow comes from his own side. But this is not what makes McCain honorable. What makes him honorable is his coherence and commitment. His words and acts dignify politics when Trump and his supporters keep trying to drag politics through the sewers.