Earlier this week, as part of a conversation about tax reform and the intricacies of my personal spending habits, Jamie Dimon explained how an extra $10,000 in my pocket would make America great again. A new poll had just come out showing that Americans oppose the G.O.P. effort by nearly two to one, with almost two-thirds saying it would primarily benefit the wealthy. But Dimon, the chairman and C.E.O. of JPMorgan Chase, the nation’s largest bank, was much more sanguine. “It’s not a bad thing, anyway,” he continued, shrugging off the criticism. “It’s hard to explain to people and to demonstrate to them how it helps the economy, but it does.”

Most economists are skeptical of trickle-down schemes—been there, done that—and might call this blind faith. Dimon called it common sense. “Cumulatively over time, it will all be re-invested money,” he said on the phone from Washington, D.C., where Republicans in Congress are currently working to reconcile the Senate and House versions of the tax-reform bill. Dividends and stock buybacks are just different ways of “re-allocating capital to other owners who use it again,” he argued. He posited that, over time, some of that money could go into venture capital or toward building a research and development center—in this country, as opposed to overseas—or into a new manufacturing plant. Corporations might not share the bonanza with their workers directly, Dimon conceded, but the money would benefit the American people eventually. “Capital spending,” he said, is what “drives productivity . . . [and] productivity drives wages. That’s why you have this debate of people saying 70 percent of it will go directly to wages. Over time, that’s probably true. It just won’t be true tomorrow.”

You can understand why Dimon, who has described himself as “barely a Democrat,” might put his pocketbook above the party. While Nancy Pelosi called the Republican legislation “Armageddon” and “the worst bill in the history of the United States Congress,” JPMorgan stock is up almost 60 percent since the election, in anticipation of deregulation and tax cuts—something Dimon said the country should have done years ago. Cutting the corporate tax rate to 20 percent, from 35 percent, he told me, is just “table stakes” for making sure American businesses are on an equal footing with those in the rest of the world now that the global economy is so competitive. He thinks that had the United States reduced corporate taxes seven years ago, “you would’ve retained a lot more companies”—he cited an Ernst & Young study that puts the number of companies lost to overseas locations at 5,000—“and capital in the United States.” That capital, he insisted, would have been used to increase both productivity and wages. “That connection is real,” he said. “It’s indirect. I can’t prove it to you, but I know it’s true.”

Wall Street, despite being the left ventricle of capitalism, is dominated by Democrats—a fact that has inspired plenty of cognitive dissonance in the last year, and especially so as the tax plan has winded its way through Congress. Dimon, for one, has several quibbles with the two tax plans now being reconciled in Congress. He said he wouldn’t eliminate the estate tax (which will benefit his heirs) and wouldn’t mind seeing his personal tax rate increased. He isn’t concerned about the national debt (more than a third of which we owe to “ourselves”), but worries that medical entitlements will consume G.D.P. growth. He argued that hedge funds and private-equity funds, which make up many of his bank’s biggest clients, shouldn’t benefit from a lower “carried interest” rate, but defended as “morally right” the Republican plan to eliminate a deduction for state and local taxes. “I get why people might say it’s essentially Arkansas subsidizing the Jamie Dimons of the world,” he said, “and why they think that’s not right. And there’s an argument that New York sends more taxes to the government than they get back. Well, of course. That is what a federal tax system is. If you’re a rich city and the average income is $200,000, you’re going to send a lot more to Washington than the poor city.”