Well, he was certainly another candidate who incites controversy that's for sure, but remember, he was a product of his times. I hate to keep harping on about Mos Maiorum but it really is central to understanding roman political psyche. Clodius did nothing unprecedented, its just whatever he did, he did to the extreme or so the sources would have it appear on the face of it. His credentials were pristine and why he would seek to have himself "demoted" is unclear. The common explaination is that he sought the office of tribune. The process of demotion to another class was called "Relegatio", and the fact that there was a legal mechanism in place in order for him to do so indicates that he was not the first.
Clodius was critisized for employing gangs to ensure things went according to "plan" in the forum. This he certainly did but why he did and how he employed them is unclear. Again, he was not the first to do this, Sulpicius was. Sulpicius employed 600 men whom he called his "Anti-Senate" to afford himself protection. The office of tribune was supposedly sacrosanct but upto Clodius' time there was a significant list of dead tribunes, dead at the hands of senate partisans. What would you or I do if in the same position?
His legislative agenda was not as radical as some had feared it would be. There was legislation to bring back guilds that had previously been banned (under Sulla I think), and there was the free distribution of grain once a month to the poor. These first two are clearly aimed at building a solid and significant client base. Other legislation included privelege against arbitrary punishment without due process, curtailing religion and its power to stop assemblies from meeting on "unlucky" days.
After his tribunship there was political deadlock in the forums, often involving running battles between the gangs of Clodius and the professional gladiators hired by the senates man, Milo. Clodius carefully followed the cursus honorum and was clearly aiming for higher office (at the time of his death he was running for Praetor), makes you wonder what he'd have done as consul!
In the end he was a solid "populares" politician, most certainly not Caesar's man as some have made out to be but was certainly leaning that way as he was obliged to tow the family line after his brother, Appius, pater familias, went to the conference of Luca and came back as one of Caesar's "men".