Congressional Democrats released a proposal on Thursday to generate an estimated $635 billion in federal revenue over a decade by levying a 10-percentage point tax on incomes above $2 million for married couples or above $1 million for individuals.

The “Millionaires Surtax,” introduced by Sen. Chris Van Hollen and Rep. Don Beyer, would only apply to the richest 0.2% of Americans, and the revenue would likely be used to make new investments in education, healthcare, and infrastructure.