How are you supposed to collect data about the future, and can i please have tomorrows lottery numbers?![]()
And there in lies one of the problems.

You can say what you like in many cases because no one can really contradict you. Once the votes are counted and the decision made what happens in the future can't stop that so it's a win win for the ones that want change, even if every positive thing they say ends up being ********.
That said there are some datapoint that can be used from the past/present for some of the arguments.