Donald Trump's Tax Plan does lower the cost of government without making it smaller. He wants to eliminate wasteful spending. Then he adds lower tax rates. For the people that will have zero taxes has the opportunity to add circulating money to the economy. 

Kindly recall when President Obama lowered the social security tax. It was 2 percent. The idea was to add cash to the economy to push the recovery along. It worked. People had higher disposable income at all income levels across the board. When that ended Walmart had a hissy fit because many of their customers would no longer have disposable income.

That is similar to the Trump Tax Proposal. It removes tax burden for couples under $50,000 per year. That is a lot of money back in a couples piggy bank that can even lead to home ownership. 

The payroll deduction alone is enough to stimulate growth in a significant way. Nothing else has to be done. It's easy.