it’s already known that progressives are less happy than conservatives
Possible explanation: People who are happy with status quo are more likely to end up defending it; people who are unhappy with status quo are more likely to end up trying to change it.
If your argument is that politics causes people to be happy/unhappy, that would require evidence beyond correlation, which itself is easier to explain by causation in the opposite direction.
(I think it is possible that you are right, but the correlation itself it not good evidence in your favor.)
Possible explanation: People who are happy with status quo are more likely to end up defending it; people who are unhappy with status quo are more likely to end up trying to change it.
If your argument is that politics causes people to be happy/unhappy, that would require evidence beyond correlation, which itself is easier to explain by causation in the opposite direction.
(I think it is possible that you are right, but the correlation itself it not good evidence in your favor.)