Guaranteeing versus being very very comfortable about something are very different positions.
I can guarantee you that the Voice increases uncertainty
This is an objective fact
Any corporate finance textbook / journal will tell you that uncertainty = risk = increased discount rate = reduction in valuation
I can't help you understand 2, but hopefully you are able to learn it post fact from the movement of the market
If voice passes, uncertainty will increase
If voice fails, uncertainty will be removed
If you are are not sure what uncertainty means, refer to the below.
I am guessing you were also guaranteeing or being very very very comfortable that the Heritage Act wouldn't result in the below? Well it has, and this sought of uncertainty commands a risk premium in the eyes of the market