Aren't you assuming that all you can do to protect your 50k is vote? And that all votes are independent? What if you could spend 25k mobilizing your side in the election? Or running an issue ad? You gain it all back and then some.
Still seems like a low return on investment, especially when you multiply by the risk of failure. Yes you can increase your investment and reduce the risk, but the ceiling on gains make this unappetizing.
On the contrary, you currently get far more leverage out of your money by participating in the (US) political system and flashing cash than you do by apathy. And the more money you spend, the less risk there is.
Why is there no net neutrality bill? The rich are overrepresented in our system for a reason. Sad but true.