Since the top wage earners pay most of the taxes....if you lower any tax the top is going to get some benefit simply on how our tax system works. In the end it all comes down “How to grow the economy” Democrats prefer Govt collecting taxes and handing out specific dollars like a big Infrastructure Bill or simply double the Child Credit subsidy. Just hand out money which people will spend and that will energize the economy. People like me say that is simply a one time fix and does add GDP in the long term. It won’t start a new factory, expand a business, sell more planes or help invent the next great technology company. 
The fight is over who is better at growing the economy....business, entrepreneurs, scientists or Joe the Pluming with a few thousand in his pocket. With 47% already not paying taxes....and the top 10% paying 80% of all taxes.....squeezing the top even more will be a zero sum game.