That is an easy one. Scientists are good at objective truth, facts, etc.
Most political decisions are however highly subjective, and based on values, principles and opinions.
Scientists are great for advising politicians on things that are obviously and provably correct or false, but once it gets beyond that, their biases tends to get in the way.
Asking a scientist if NASA should get more or less funding is about as useful as asking the chief bishop if the church should get state funding as a silly example.
And non-scientists take a more rational, balanced view that is more free from bias?
I think bias is intrinsic to being human, and unavoidable (all we can do is mitigate its damage). But someone who can admit they are wrong when faced with evidence (aka a scientist) is probably better equipped than one who is adamant that if they keep saying "no", eventually the universe will shut up and behave (most politicians).
Most political decisions are however highly subjective, and based on values, principles and opinions.
Scientists are great for advising politicians on things that are obviously and provably correct or false, but once it gets beyond that, their biases tends to get in the way.
Asking a scientist if NASA should get more or less funding is about as useful as asking the chief bishop if the church should get state funding as a silly example.