Speaking through the night, Senator Ted Cruz, with heavy-lidded, sleep-deprived eyes, conveyed not the libertarian element in Republican philosophy that advocates for smaller government and less intrusion into the personal lives of citizens. but a new, virulent strain of empty nihilism: “blow it up if we can’t get what we want.”

This recent display of bomb-throwing obstructionism by Republicans in Congress evokes another painful, historically embarrassing chapter in the Republican Party — that of Senator Joseph McCarthy, chairman of the Senate Permanent Subcommittee on Investigations, whose anti-Communist crusade was allowed by Republican elders to expand unchecked, unnecessarily and unfairly tarnishing the reputations of thousands of people with “Red Scare” accusations of Communist affiliation. Finally Senator McCarthy was brought up short during the questioning of the United States Army’s chief counsel, Joseph N. Welch, who at one point demanded the senator’s attention, then said: “Until this moment, Senator, I think I never really gauged your cruelty or your recklessness.” He later added: “Have you no sense of decency, sir? At long last, have you left no sense of decency?”

Watching the Republican Party use the full faith and credit of the United States to try to roll back Obamacare, watching its members threaten not to raise the debt limit — which Warren Buffett rightly called a “political weapon of mass destruction” — to repeal a tax on medical devices, I so wanted to ask a similar question: “Have you no sense of responsibility? At long last, have you left no sense of responsibility?”