Yeah, Old Shevie created an idea that the jedi were trying to take over, and since he seemed a nice guy people believed him, and the jedi did nothing to prove him wrong when they had the chance. Also if you read the ROTS novel, his trick with the tape was pretty clever, but also showed that the jedi just went in and were like "you're under arrest" with no proof they could give the senate.
That just goes to show how much people want to trust that the government works.
What tape?
Yeah.....that was kinda dumb.