Sure you can talk about politics. Its just that very few people who grew up in China have interesting things to say on the subject. I'm sure you'll get great responses about the glorious 5000 years of history or changing china's peaceful rise and don't get them started on Japan or even better Taiwan...its amazing in a country of 1 billion almost everyone I talk to has the exact same view on these topics, sometimes word for word.

The absolutely top notch, best educated, well traveled people can be interesting to talk to about politics, as can the extremely uneducated, they are the only two groups I've found who are willing to express opinions different from CCTV. Also in the south people are much more expressive and open about these things than they are in the north.