The difference between Bitcoin's vulnerability and democratic systems is pretty clear: in a democratic system, 51% of the participants control the outcome; in

The difference between Bitcoin's vulnerability and democratic systems is pretty clear: in a democratic system, 51% of the participants control the outcome; in Bitcoin, a single participant doing 51% of the work can control the system. It is equivalent to allowing every single voter to fill out as many ballots as they can on election night, using whatever equipment they happen bring with them.