You are right in your intuition that government and science are not the same thing. Politics deals with power and subjective perception of values. Safety versus liberty is not something you can prove one way or the other, different people have different expectations from society and we try to develop political and leadership systems that account for those preferences.
When you go overboard is using politics to decide on issues other than values. For example, we have widely decided that poisoning people is bad. Some amount of harm is inevitable in the real world, and we have set (purely political) limits on acceptable risk, say, one in a million that you get cancer.
Once that value decision is made, the job of politics stops, 1 in a million cancer risk from Asbestos is the same as 1 in a million from second hand cigarette smoke. It's irrelevant how many people work in the cigarette industry, it's importance to the GPD, how well connected politically are the cigarette manufacturers etc. The risk becomes a pure scientific fact that is not amenable to political negotiations.
When you go overboard is using politics to decide on issues other than values. For example, we have widely decided that poisoning people is bad. Some amount of harm is inevitable in the real world, and we have set (purely political) limits on acceptable risk, say, one in a million that you get cancer.
Once that value decision is made, the job of politics stops, 1 in a million cancer risk from Asbestos is the same as 1 in a million from second hand cigarette smoke. It's irrelevant how many people work in the cigarette industry, it's importance to the GPD, how well connected politically are the cigarette manufacturers etc. The risk becomes a pure scientific fact that is not amenable to political negotiations.