If you care about American politics and being outraged at every and any thing thrown at you during the day, it is active enough. However you are SOL if are curious about any other topic that does not involve narcissistically talking about yourself.
Assuming you are invested enough to find or create a community for a topic you care about, be prepared to be talking to yourself for a long time and consider yourself lucky if you manage to get 2 other people commenting on it.