A witness appearing before the Democratic National Committee's Platform Committee on Thursday said that raising taxes by 80 percent would not impact economic growth.

Heather Boushey, the chief economist and executive director of the Washington Center for Equitable Growth, said that raising taxes to nearly twice the current level on some would not hurt America's economic growth according to a paper by a colleague of hers.

"And let me end this by noting Emmanuel Saez, one of the nation's foremost tax experts, is on my steering committee and he did a paper with a couple of his colleagues a few years ago, really documenting that we could, and get this, hold onto your seats, raise taxes at the top by upwards of 80 percent and not have any negative effect on economic growth," Boushey said.

"Now, granted, that's an empirical paper, it's modeling exercise, but I think that what we're learning from the most cutting edge, serious, empirical research in economics is that there's a lot of room to do more at the top."

Many Democrats want to raise taxes on the wealthy, and in some cases on other economic groups. This has been a key issue in the 2016 presidential election cycle.