WASHINGTON—Democratic presidential candidate Michael Bloomberg is proposing tax increases on corporations, top earners and estates that would make the wealthiest Americans foot the bill for programs in areas such as education, infrastructure and climate change.

In broad strokes, Mr. Bloomberg would reverse some of the 2017 tax cuts enacted by Republicans and President Trump and then raise taxes further, aiming to tax investment income at the same rates as labor income. Some details are still fuzzy, but the campaign estimates...