The Trump tax cut is a gamble at two levels. In the short term, the GOP is hoping that the small increase in net earnings that most people will experience will give them a boost in the 2018 elections even though the bill will cost other people money and primarily benefit the donor class. In the long run, the hope is that the bill will encourage new investment to the point that productivity and wages will rise dramatically and the deficit will actually fall.
Will it work? The evidence thus far predictably indicates that most of the corporate tax cut will be spent on dividends and share repurchases, not on new investment. As a result, asset prices will rise and inequality will increase. The scene will thus be set at some point for the next Great Recession, not a productivity boom.