WASHINGTON

Michael Bennet was supposed to be going off a cliff in Vail.

But instead of his usual New Year’s trip to a ski lodge with his wife and three daughters, the junior senator from Colorado found himself in a strange, unfamiliar place in the middle of the night: breaking with the president and his party to become one of only three Democratic senators and eight senators total to vote against President Obama’s fiscal deal.

“I was a little surprised that the margin of the vote was so big,” said a weary Senator Bennet, who seemed a bit taken aback to be such an outlier. He was munching on a late-afternoon cheese steak sandwich at “George’s, King of Falafel and Cheese Steaks.” (The senator loves falafel, which his girls call “feel awful.”)

“I almost ordered extra cheese,” he said sheepishly, “but I would have been embarrassed.”

Long before Bennet came to work in the “land of flickering lights,” as he mockingly calls the dysfunctional nation’s capital where he grew up, Frank Capra dreamed him up. In a Congress that has become opéra bouffe, Bennet is the freckled blond choir boy singing a cappella. The 48-year-old senator looks like the Yale law student he once was, wearing a Jos. A. Bank plaid shirt, gray sweater and khakis. “These are the only clothes I have in Washington that’s not a suit,” he grins.

As Katherine Boo wrote in The New Yorker, back when Bennet was the crusading Denver schools superintendent, his open face and amiable manner “only partly masked the intensity and severity of his judgments.” He was, Boo wrote, “an overachiever. He liked to announce improbable goals, then defy expectations of failure.”