From Robert Reich, influential economist and former Department of Labor Secretary:

Contrary to what you hear from Republicans and Fox News, this bill will NOT help the economy. Over the last 50 years, Congress has passed four major tax cuts, and every single one proved that “trickle-down economics” is nothing but a cruel hoax.
The nonpartisan Congressional Budget Office confirms that if this bill becomes law, those in the bottom tenth of the income distribution will end up poorer, while the top tenth will be substantially richer.
Never before in the history of this nation has such a large redistribution of income been directed upward, for no reason at all except to benefit those with wealth and power.