Sen. Bernie Sanders and Rep. Ro Khanna plan to introduce a bill to impose a 5% federal wealth tax on billionaires, according to the senator's office.

The push from Sanders, I-Vt., and Khanna, D-Calif., for a federal wealth tax comes as the idea of taxing billionaires gains cachet in Democratic states across the country. While progressives like Sanders have long called for taxing the rich at higher rates, many Democrats are now seizing on refreshed anti-billionaire animus as they campaign against Republicans and President Donald Trump on an affordability agenda.

"At a time of unprecedented income and wealth inequality, this legislation demands that the billionaire class in America finally pay their fair share of taxes so that we can create an economy that works for all of us, not just the 1%," Sanders, the ranking member of the Senate Committee on Health, Education, Labor and Pensions, said in a statement.

"Enough is enough. Billionaires cannot have it all. It is time to enact a wealth tax on billionaires and use this revenue to address some of the major crises facing working families, the children, the elderly, the sick and the most vulnerable," Sanders said.

According to Sanders' office, the planned tax would raise $4.4 trillion in federal revenues without hiking taxes on any Americans with a net worth of less than $1 billion. The revenue would then be invested to benefit working families, children, the elderly and other vulnerable populations.