Having a mental illness -- say depression or deep anxiety shouldn't disqualify someone from voting.
In fact, how does one test for this or monitor this at the polls?
A bigger problem is stupid people voting, and VA has a lot of that. For example, voting for Trump. The RepTrolls are in a panic because their party is imploding. Republican extremism is going to hand this election to Hillary.
You want to see what hard core conservatism does? Read this case study on Louisiana
https://www.washingtonpost.com/news/wonk/wp/2016/03/04/the-debilitating-economic-disaster-louisianas-governor-left-behind/
Ain't it great to watch!!!