A Lack of Trust will be the Problem
It won't take too many articles like this, and similar threads in social media to destroy the public's trust in electronic voting. If the people lose trust in the voting system then they will have no trust in the political system (or even less than there is now).
While it may be possible to build a secure voting system it will have to use some complex encryption techniques. Good luck explaining them to the public so that they trust the system.