Here's the reason:
There was also seeding, watering, mowing, building the sand traps and driving bulldozers, mini-excavators and loaders — all while they earned about $10 an hour or less, they said.
Around that time, a licensed heavy equipment operator in central New Jersey would have received an average of $51 to $55 per hour in wages and benefits, according to union officials at the International Union of Operating Engineers Local 825 in the nearby town of Springfield.
Trump saved a huge amount of money by using the undocumented workers. As always, his own wallet is his only concern, laws be damned.