It’s quite likely that Donald Trump was unaware that payroll taxes are how the Social Security and Medicare trust funds are bankrolled. He might also be unaware that current Social Security checks to seniors are derived from payroll taxes — not those paid into the system when today’s recipients were working, but the ones being paid in, right now, by today’s workers.
Either Trump doesn’t know how the programs work or he’s deliberately attempting to use executive orders to kill both programs, in accordance with the decades-long conservative crusade to drown them in the bathtub, leaving current and pending retirees without the benefits they’re expecting.