You definitely want to avoid the appearance of someone who's just looking for the "greener grass" on the other side of the fence. The interviewer, who doesn't know anything about you or your current workplace, may wonder if the source of your current problems is the workplace or if the problem is really you. I've certainly known a few toxic co-workers who left the company because they thought the workplace politics were terrible. More often than not, things got a little better after they left.
So, first of all, focus more on your goals and desires than your current job's problems. Make this more about finding growth rather than avoiding stagnation. Forget the interviewing questions for a bit, forget the terrible politics of your current place. Ask yourself what you'd want from any job right now.
Expect to be asked about working under difficult conditions. If I were interviewing you, and I knew anything about what you stated in this question, I would certainly be asking you questions like "tell me about a time you had to work with a difficult co-worker (or difficult work situation)". Two reasons why: one is to find out how you might approach a bad situation, the other is to make sure you're less likely to be the workplace antagonist. If, in answering the question, you made it seem like the other people were somehow stupid or beneath you, or if you went "cowboy" and went behind everyone's back, that would be a red flag to me. You'll never avoid co-workers you don't get along with or office politics. It's important to find an employee who's going to be able to do his/her job even when things get a little tense. And not take his ball and go home when he doesn't like the way the game is going....
And also remember that you are interviewing the company as well. This is the time to make sure the grass is really greener, and you're not just leaving one messed up workplace for another. Ask people about the work environment. Ask them about what their typical day is like: how much time do they spend doing real work vs. having meetings or doing bureaucratic tasks. Make sure this is the place you want to spend a good bit of your waking life.