I think it is a matter of politeness.
I would suggest: As a guest / host just wait and see if the host / guest himself
starts to discuss politics, and even then it would be impolite to discuss
politics too heatedly. If it becomes heated then one should rather back off. I
am sure there are lots of other topics out of which a host and a guest could
create a mutually fulfilling conversation. Also consider that a guest is somehow
dependant on the host, so that a host how pushes his guest within a conversation
could put the guest into a really awkward position.
Greetings from Germany,