The Overton window can't just be applied to public political discourse. The concept applies to political corruption acceptability too.

Nixon was run out of office for 13 minutes of illegal recording. During Obama we found out they were illegally tapping every domestic phone conversation during multiple presidencies including both parties. There was barely a peep among the general public and nothing changed when we found out. No prison, no trials, the only person I remember losing their job was Snowden for telling us.