The current campaign against the bot (a bot which only started this week) is being run by a new account @iflagshit and seems to be fashioning itself as a Poor man's @berniesanders. If it is Bernie, I would be surprised that he would buy delegation from @blocktrades.

It's obvious why. Such a purchase would be off-chain. Whoever bought the delegation wishes to hide their identity. It could be someone trying to discredit @berniesanders.