Would love this. However, I have visions of Russian, Chinese, Iranian, and North Korean agents easily changing actual votes at will. Not even a real technological challenge to them, so far as I know.
If others know more and have more up-to-date information about how voting websites can have essentially perfect security, I'm eager to learn more. Typically, to my knowledge, network security experts will hedge hard and stay far away from promising perfect security -- and they'll say things like "any security measure can be beaten".
And no, those who would hack into stock-trading sites and such would be far less capable and motivated. So the existing level of security for stock-trading sites and such, I would think, is not comparable. Yes, even though it's big dollars.