Expats are expats for a reason. They tend to not be aligned with the domestic views of the country they left. Often the leave exactly because their politics are incompatible with local ideology.
Depends why they're expats so "they tend to" have lots of different reasons for immigrating. Iranian Nuclear scientists living abroad have different reasons for doing compared to Americans living in Tijuana. Culturally, there's a tendency to be more conservative to keep the values and norms of the old country, when the old country has moved on.