Calling Trump's tax cuts "supply side" is laughable. Reagan really did reform the tax system, and cut rates significantly while closing loopholes which made things more equitable all around. Trump's tax cuts are concentrated almost totally on corporations, when there is zero evidence that giving corporations more money will cause them to hire more people or give raises - just look at the crickets when Gary Cohn was addressing a roomful of CEOs a month ago and he asked for them to raise their hands if they they were going to use the windfall to hire more people or increase investment and only a few did causing him to ask "where's the rest?"
A couple companies offered well-timed "we're giving workers $1000 bonuses thanks to the tax cut", one of them being AT&T. Then the next day (today) AT&T announced they were laying off 700 installation techs. Because that's the thing, companies only pay workers enough to hire/keep them, they aren't going to pay them more just because they can afford it. They only hire enough workers to do the work they need done, they aren't going to hire extra workers just because they can afford it. The tax cuts will go toward stock buybacks to raise their stock price, so that the executives who are compensated based on the stock price either directly or indirectly can get richer.
Even Laffer conceded that his curve on a napkin claiming tax cuts will increase economic growth enough to pay for themselves was written in the late 70s when the top tax rate was 70%, and wouldn't hold at significantly lower rates.