Sen. Elizabeth Warren (D-MA), one of several Democrats running for the party's nomination in the 2020 presidential race, has outlined details progressive policy ideas on workplace issues including government financial support to working parents to cover child-care costs. Drew Angerer | Getty Images

Elizabeth Warren, the economic policy pacesetter in the Democratic presidential primary field, wants to raise $1 trillion in government revenue from a new 7% surtax on profits of the largest corporations. What the Massachusetts senator dubs the "Real Corporate Profits Tax" would apply to worldwide profits exceeding $100 million. The purpose, she says, is to bolster government coffers by preventing corporate giants from exploiting loopholes to avoid federal taxation following the large tax cut enacted by President Donald Trump and a GOP-controlled Congress in December 2017. "It will make our biggest and most profitable corporations pay more and ensure that none of them can ever make billions and pay zero taxes again," Warren wrote in a Medium post published Thursday morning. "To raise the revenue we need — and ensure every corporation pays their fair share — we need a new kind of tax that big companies can't get around." The Trump tax cut, following entreaties from corporations for a more globally competitive U.S. system, reduced the top corporate rate to 21% from 35%. But deductions remaining in the IRS code allow some large corporations to reduce their effective rates far below that — in some cases all the way to zero. Read more: Elizabeth Warren's 2020 campaign raises $6 million in the first quarter Watch: How Amazon paid $0 federal income tax in 2018

Warren cited two high-profile examples: Amazon has reported $10 billion in 2018 profits but zero in U.S. corporate taxes; Occidental Petroleum has reported $4.1 billion in profits and also paid zero. Her new surtax would prevent them, and other corporations with profits exceeding $100 million, from wiping out their tax liabilities. Instead of taxable corporate income as defined by the IRS, the 7% surtax would apply to profits companies report to their investors. "Amazon pays all the taxes we are required to pay in the U.S. and every country where we operate, including paying $2.6 billion in corporate tax and reporting $3.4 billion in tax expense over the last three years," an Amazon spokesperson said. Because stock values and executive compensation turn on those public reports, Warren reasons, corporations don't obscure their real profits to shareholders with the write-offs they use for the IRS. Those include large deductions for depreciation, the value of stock options and overseas tax shelters. The new surtax would be separate from the existing corporate tax. If applied in 2018, Warren said, Amazon would owe $698 million and Occidental Petroleum $280 million.