Everyday Americans are being left behind because of President Donald Trump's tax cuts — and one solution could be to tax the rich, civil rights leader and two-time presidential candidate Jesse Jackson Sr. told CNBC on Wednesday.

"There must be some kind of wealth tax," the president and founder of the Rainbow PUSH Coalition said on "Closing Bell."

However, he didn't endorse any specific ideas laid out by his fellow Democrats.

Democratic presidential candidate and Massachusetts Sen. Elizabeth Warren wants to impose a 2 percent tax every year on households with assets of more than $50 million and 3 percent on households with assets of more than $1 billion. Meanwhile, Rep. Alexandria Ocasio-Cortez, from New York, wants to slap a 70 percent marginal tax rate on income above $10 million. And Sen. Bernie Sanders, an independent from Vermont who launched his 2020 presidential campaign Tuesday, has proposed a big hike in the estate tax, including a 77 percent rate on estates of more than $1 billion.

Jackson, who rose to prominence during the 1960s civil rights movement, said the wealth gap is real and wasn't helped by the new tax law.

"The big tax cut — it all went up and less went down," said Jackson, who ran for the Democratic presidential nomination in 1984 and 1988. "The 1 percent is getting much richer and that gap is not good for democracy."

His organization is currently hosting its 22nd annual Wall Street Project Economic Summit in New York to address issues like the racial wealth gap and diversity in corporate boards.