Ms. Warren would also increase her wealth tax on billionaires to 6 percent of the value of all their assets above $1 billion, up from her previous proposal of 3 percent. And she would assess a tax on corporations that roughly equates to what they currently pay for employees’ health care, with a slight savings.
Ms. Warren says none of those tax increases would hit the middle class. Republicans mocked that claim.
“Hahaha,” Senator Ben Sasse of Nebraska said in a statement. “This make-believe math is bonkers.”
Many analysts, including some Democratic economists, say it is unclear if Ms. Warren’s combination of new taxes — including some never tried at this scale in the United States — can raise anywhere close to the revenue she estimates.
Perhaps the biggest unknown is how the capitalist American economy would function with levels of taxation and spending more comparable to the social democracies of Scandinavia.
“It’s as much an art as a science, trying to figure out the economic effects of policies we haven’t seen before,” said Diane Lim, a former economist for congressional Democrats and senior economist at the White House Council of Economic Advisers, who now works for the Penn Wharton Budget Model. “I’m worried it’s unrealistic. It’s just unknown.”
Polls suggest a wide range of Americans support raising taxes on the rich, and in particular a tax on the very wealthy. They also show increased numbers of Americans saying the government should do more to help them. Those trends, in addition to the concentration of wealth at the very top, are helping to drive Democrats toward more efforts to tax the rich and redistribute through the government, said Gene Sperling, a National Economic Council director under Mr. Obama.
“The expansion of economic concentration and wealth inequality has put a greater focus on the top one-tenth of 1 percent,” Mr. Sperling said, “both because of the obscene economic inequality it signifies and as a practical matter, there is just more revenue to capture there than 30 years ago.”