I mean....I kinda blame whoever had a five minute conversation with Jar Jar and came to the conclusion "we should put this guy in a political position" (so I guess basically the average voter)
yeah the whole galactic senate is extremely dumb. it's a surprise it didn't collapse sooner. representation is not proportional at all, they spend all their time flying around on little disks and making speeches instead of doing any legislating or planning. Not sure why you made a jab at voters when the problem is clearly that the system is lopsided and undemocratic and has no legitimacy.
He supported Naboo settler state and their Republican overlords over the Trade Federation invaders in classic colonial war, later himself even becoming the comprador token native in Republic Senate.
He was a patsy who was manipulated into doing the bidding of a Sith Lord who had already orchestrated a galactic civil war and gotten away with it. He did a bad thing but he meant well and nobody else could reasonably done better in his situation.