Just 14% say they have a great deal or "quite a lot" of confidence in the criminal justice system, half the level of a decade ago.
Manhattan District Attorney Alvin Bragg's case is the first of several involving Trump as the country braces for a 2024 presidential election in which Trump is the leading Republican candidate.
Trump himself has over the years complained that law enforcement was targeting him for political purposes, and his rhetoric has heightened since the New York case surfaced.
On Wednesday, Trump called on his fellow Republicans in Congress to slash funding for the U.S. Justice Department and the FBI.
"It's obvious the criminal legal system can punch down - it's proven that, and oppressively so," Ali said.