Are political/ideological reasons for career moves acceptable in academia? Suppose one is happy at one's institution until something happens that makes it impossible to stay given one's strong ideological beliefs. Is it a good idea to mention these beliefs if they are the main reason for wanting to move? 

For example:


"Why do you want to study at this university?" Because this university is in Russia and I approve of Putin's actions as President.
"You've worked at this institution for 10 years. Why do you want to leave now?" Because it's in the UK and after the Brexit referendum, I no longer feel welcome here.


Nothing special about these examples; one could equally have "I want to leave Russia because I disapprove of Putin's actions as President" etc. 

I tag this with "academic life" because it could apply to any decision to move.
A political or ideological answer, albeit honest, is usually a missed opportunity to make a point about the move being a good academic fit. 

Your goal as the candidate in this kind of exchange is not just to answer the questions accurately; it's to answer the questions accurately while also trying to convince the committee that you are the right person for the position. Virtually any question can be used to make a point about how excited you are about the institution you'd like to move to, how much you can contribute given your past experience, etc. A political answer doesn't usually help you "sell" yourself.

For example: 


Why do you want to study at this university? "Because I'm really interested in the work Professor Twist is doing on basket weaving in extreme underwater conditions."
Why do you want to leave your current institution? "Because I am looking to gain expertise in the hot new field of basket weaving in extreme underwater conditions, and your faculty are the best in the world in that area, while my current institution  doesn't have anyone working in this field." Or "Because I am really interested in working with Professor Twist, I think that with my background in freshwater basket weaving I could contribute to her research in an exciting way."


So even a completely non-controversial political or ideological reason is not necessarily the best reason to use in answer to this kind of question.