Defcon hackers have no problems hacking voting machines.
https://www.engadget.com/2017/10/10/defcon-event-reveals-ease-of-hacking-voting-systems/
excerpt:
The report writers reach a few conclusions. To begin with, it's clear that dedicated hackers would have no trouble getting in – if neophytes can hack a system after a brief learning curve, it'd be a walk in the park for state-sponsored hackers. They also warn that foreign components or software could add to the risk by giving ne'er-do-wells a chance to slip in malware that compromises an entire platform. And crucially, politicians, non-government groups and other experts should be involved to make sure that voting system security is treated seriously.
The question is, will the right people listen? It's hard to say. Key US officials did visit the voting machine village, including Homeland Security officials and Congress members like Rep. Jim Langevin and Rep. Will Hurd. And some states are already aware of security risks: Virginia is replacing one of the machines hacked at DefCon. The problem is that many politicians not only didn't attend, but are sometimes clueless about security. A truly comprehensive fix would involve a major, nationwide rethink of election security practices, and that may not happen so long as many of those in power don't take the problem seriously.
I'm looking for their 'report'…