If I was it'd be an irrational commitment towards some set of ideas that I'd use after the fact to explain why I am, like I do to explain why I'm not. I only like the part where God delivers the faculty of reason through a Creationist scheme that leads to our ultimate uniformity.
Humans are adept having a emotional reaction then Justifying Ex post facto.
Someone maybe a rationalist when it comes to religion, but they are irrational about something else.
Most likely in the political realm.
I trust my capacity to reason and I know it's the only tool at anyone's disposal to make sense of the world. Most of my friends are the same. We're not a community, we don't think much about it, it's so obvious.
How do you want me to vote if I consider myself a "rationalist" in that I apply many principles from the Sequences to my life, but am not part of the "community" in that I have spent maybe 5 minutes TOTAL of my life in the presence of another rationalist?