Even if his polling numbers don’t budge, Sanders still has an important role to play in the Presidential race. PHOTOGRAPH BY MANDEL NGAN / AFP / GETTY

From the beginning of Saturday night’s Democratic debate, Senator Bernie Sanders was very clear on what he wanted to talk about. He began with two sentences about the terrorist attacks in Paris, expressing his horror and disgust, then he moved onto his main message: “I’m running for President, because as I go around this nation, I talk to a lot of people. And what I hear is people’s concern that the economy we have is a rigged economy.”

It was an awkward transition, and not one most politicians would have made. Rather they would have devoted, as Hillary Clinton and Martin O’Malley did, their entire opening statements to the attacks, seeking to come across as empathetic, resolute, and ready to take over as Commander-in-Chief. But Sanders isn’t like most politicians, and he sometimes doesn’t abide by the often stultifying conventions of modern Presidential elections.

Congenitally averse to political theatrics, he reportedly didn’t practice much before the first debate, and it showed. This time, according to a Times article published on Friday, he agreed to do some real prep work, taking part in serious and lengthy rehearsals, with a staff member playing the role of Hillary Clinton. Perhaps as a result, he looked sharper. His answers were more direct and, unlike in the first debate, he didn’t make any off-the-cuff remarks that risked diverting attention from his message that America’s economic and political systems are broken. In a debate that was inevitably somewhat overshadowed by the aftermath of the terrorist attacks, what he was saying came through loud and clear.

The first question put to him on domestic issues was about taxation and how far he would go in raising the top rate of income tax on well-to-do Americans. “In the last thirty years, there has been a massive redistribution of wealth,” Sanders said. “And I know that term gets my Republican friends nervous. The problem is, this redistribution has gone in the wrong direction. Trillions of dollars have gone from the middle class and working families to the top one-tenth of one per cent who have doubled the percentage of wealth they now own.”

It was a timely history lesson, but it didn’t answer the question. Nancy Cordes, CBS News’s congressional correspondent, pressed Sanders, saying, “Let’s get specific. How high would you go?” Sanders paused for a moment and replied, “We haven’t come up with an exact number yet, but it will not be as high as the number under Dwight D. Eisenhower, which was ninety per cent.” Laughter and applause rang out around the arena. “I’m not that much of a socialist compared to Eisenhower,” Sanders went on.

Perhaps the seventy-four-year-old Larry David look-alike from Vermont had prepared this answer; perhaps he hadn’t. In any case, it was a brilliant response, and it also had the virtue of being true, or almost true. (Actually, the top rate under Eisenhower was ninety-two per cent, even higher than Sanders said.) In addition to serving up a timely reminder of what the tax system looked like during a period now widely regarded as a golden one for America’s economy, Sanders threw into sharp relief Clinton’s tax proposals, which would eliminate tax breaks and loopholes for people earning more than two hundred and fifty thousand dollars a year, but wouldn’t raise the top rate.

The next topic of discussion was health care. Clinton said she wanted to “build on and improve the Affordable Care Act,” a position she described as “a significant difference that I have with Senator Sanders.” Sanders, who supports a single-payer system modelled along Canadian or European lines, agreed that the A.C.A. was a step forward, saying, “We have made some good progress.” Then he added, “I believe we’ve got to go further. I want to end the international embarrassment of the United States of America being the only major country on Earth that doesn’t guarantee health care to all people as a right, not a privilege.” Under the private-insurance system, he went on, “We end up spending—and I think the secretary knows this—far more per capita on health care than any other major country, and our outcomes, health-care outcomes are not necessarily that good.”

This was another strong answer, which combined an appeal to fairness and egalitarianism with a practical point. Defending his proposal to raise the federal minimum wage from seven dollars and twenty-five cents an hour to fifteen dollars, Sanders repeated the trick. Making the moral case for a living wage, he said, “It is not a radical idea to say that if somebody works forty hours a week, that person should not be living in poverty.” Then, seeking to counter the claim that setting a much higher minimum wage could cost a lot of jobs, he pivoted to a macroeconomic argument that harks back to Henry Ford. “When we put money into the hands of working people, they’re going to go out and buy goods, they’re going to buy services, and they’re going to create jobs in doing that,” he said. “That is the kind of economy I believe in. Put money in the hands of working people. Raise the minimum wage to fifteen bucks an hour.”

All across the country, Sanders supporters, and many others, I suspect, were surely saying, “Go Bernie!” Even O’Malley, the former governor of Maryland, who also had a pretty good night, seemed impressed. Backing up Sanders’s point about tax rates, he pointed out that the top rate at the start of the Reagan Administration was seventy per cent. And seizing on Sanders’s argument about introducing a living wage, he referred to Maryland under his governorship. “We did it, and it worked, and nobody headed for the hills or left the state because of it,” he said.

As the debate moved on to Wall Street regulation, Sanders sought to exploit what has always been one of Clinton’s biggest vulnerabilities: her ties to the financial industry. Asked by the moderator, John Dickerson, why he had described some of the donations to Clinton’s campaign as compromising, Sanders said: “Let’s not be naive about it. … Why, over her political career, has Wall Street been a major—the major—campaign contributor to Hillary Clinton? You know, maybe they’re dumb and they don’t know what they’re going to get, but I don’t think so.”

After Sanders repeated the insinuation in response to a follow-up question, Clinton made a slip: she cited her work rebuilding Ground Zero as a senator from New York, appearing to invoke the 9/11 attack on Lower Manhattan as a justification for accepting campaign donations from Wall Street. Or, at least, that was how a viewer who sent in a tweet (and Reince Preibus, the chairman of the Republican National Committee) interpreted her statement.

Sanders isn’t really cut out for the role of attack dog, though. Later on, when Cordes read out the accusatory tweet and Clinton sought to defend herself, Sanders rallied to her side, saying, “She worked—and many of us supported you—in trying to rebuild that devastation.” Unlike in the first debate, however, when Sanders came to Clinton’s aid on the issue of her State Department e-mails, he did, on this occasion, combine his friendly gesture with a statement distancing himself from her on policy. “But at the end of the day, Wall Street today has enormous economic and political power,” he said. “Their business model is greed and fraud. And for the sake of our economy ... the major banks must be broken up.”