… In the past, congressional hearings have been a powerful weapon. When control of the government is divided between two parties, investigations have been a vehicle for the House majority to publicly and repeatedly hammer the president. And research has found that the cumulative toll of hearings has been effective in weakening presidents, particularly as it pertains to their approval rating, so a blitz of hearings outlining the case against Trump could harm him. But then again, Trump has proven surprisingly resilient in the face of House Democrats’ investigations so far — although his approval rating is hovering around its lower bound at 41.3 percent, it hasn’t yet dipped below 40 percent, according to FiveThirtyEight’s tracker of presidential approval. There’s reason to believe that could continue even after the impeachment process goes public. CONT.
Amelia Thomson-DeVeaux, FiveThirtyEight