I'd like to offer some advice to make things go a bit more smoothly. There's a widespread view that all beliefs are political, you can't be apolitical, and anyone arguing for a belief opposing yours must be an enemy. To me, that view is pretty much a type error. Beliefs are value-neutral. Only arguments for or against beliefs can be political or not.
More specifically, some arguments are rational (based on evidence) while other arguments are political (based on who benefits and who loses). You can be a very civil person, but still reach for political arguments when defending your beliefs, and thus cause net harm. Or you can be a rude person, but drawn to arguing based on evidence, and thus cause net benefit. It's up to you.
Now go forth and make a flamewar :-)
These attributes are mostly orthogonal though. Most evidence, even if conclusive, will show that certain approaches benefit one group more than some others. There is no such thing as purely evidence-based policy, because there is no agreement on what to optimize for.
I think this whole evidence-based fad completely misses the point. It insinuates that there is a perfect possible outcome that will benefit all equally, and that is simply not the case. And by focusing on the outcomes, it detracts from the real sticking point: let's talk about how to harmonize goals, instead of only results.