Former Rep. Barney Frank (D., Mass.) called the Green New Deal a "loser" for Democrats on Tuesday, saying that kind of radical change all at once could "destabilize a society."
"I think the Green New Deal would be a loser. I do not think that people are going to be advocating that whole package," Frank said on "Squawk Box." "There's not a lot in there I disagree with ... But there's an argument that you don't destabilize a society by doing too much change at once.
"We have people who are skeptical of government, people like me who do want to expand the government role in some areas, need to understand that we have to show how that works. You have to do it in pieces, and then as you show it has worked, you can build on that," he added.
Known for his work on the Dodd-Frank legislation on financial regulation, Frank weighed in on CNBC about the growing 2020 Democratic field. He said the American people were "unpredictable" in choosing their presidents so he was reluctant to make predictions.
He said he was worried about the fringes on the right and left who thought their preferences mirrored those of the public.
Frank said he didn't think democratic socialist Sen. Bernie Sanders (I., Vt.), who officially announced Tuesday he was running for president, could be elected.
All Senate Democrats running for president have come out in support of the radical energy proposal from Rep. Alexandria Ocasio-Cortez (D., N.Y.) and Sen. Ed Markey (D., Mass.) to battle climate change. The Green New Deal proposal had a rough rollout, with Ocasio-Cortez's office releasing a derided "FAQ" on the resolution that included details like providing economic security for those "unwilling to work," putting an end to air travel and getting rid of farting cows.
The proposal itself is wildly ambitious and calls for extensive government intervention in the economy to meet the goal of 100 percent, zero-emission energy sources and the elimination of fossil fuel use. It also guarantees a "family-sustaining wage" and high-quality health care for all Americans, in addition to calling for actions like upgrading every building in America for energy efficiency and expanding high-speed rail to a point where air travel becomes unnecessary.
Republicans have attacked the Green New Deal for being impractical and pushing the country toward socialism.