Trump has argued that presidential immunity should make him immune to any criminal prosecution while in office. The Supreme Court has ruled that
the president has absolute immunity from illegal acts.
In his first term, a lot of his illegal orders were refused by subordinates on the grounds that they're illegal, but he's since announced his plan, if re-elected,
to purge the civil service and replace these subordinates with people more willing to go along with his orders.
Trump's two impeachments showed that the House and Senate will vote along party lines, so Trump would never be removed from office as long as Republicans have a majority in the Senate... which it seems they'll likely maintain.
If someone thought it was likely that Trump would win the election and is concerned that a re-elected President Trump would behave illegally to infringe their rights, exactly what recourse would they have to protect those rights?