Nick Hanauer, a Seattle venture capitalist who was an early investor in Amazon and is now a progressive activist and writer, argues that trickle-down theory should be replaced with what he and Eric Liu, a former adviser in Bill Clinton’s administration, call “middle-out economics.”

“I believe capitalism is the greatest social technology ever created for generating wealth and prosperity,” he said, “but we’ve confused what’s good for the narrow-short-term interest of a few capitalists for what’s good for capitalism.”

The notion that tax cuts for the rich are what cause economic growth and create a thriving middle class is “both wrong and backwards,” Mr. Hanauer said. “The thriving middle class is the cause of economic growth.”

The ideas that are capturing attention, particularly in the run-up to the 2020 election, focus more directly on the fortunes of workers and give the government a much more central role in spurring economic growth and distributing wealth.

The approach reaches back to the era of Franklin D. Roosevelt for inspiration. The major effort to alter the course of climate change was purposely named the “Green New Deal” — after Roosevelt’s signature policy — precisely for that reason. Several versions of the program exist, but the one introduced by Representative Ocasio-Cortez and Senator Ed Markey of Massachusetts includes “a job guarantee program to assure a living wage job to every person who wants one.”

During the recession’s grimmest months, President Obama pushed to fast-track a multibillion-dollar stimulus package — the American Recovery and Reinvestment Act of 2009 — aimed at creating jobs and spending money on transportation, technology and energy projects. Although the plan was smaller than several left-leaning Democrats wanted, it rested on a shared assumption that cranking up public investment would get the economy moving and put people back to work.