There is a soft ban on talking about politics on LessWrong, but downvoting this question without explaining why strikes me as a bad way to enforce it.

To answer the question, this may be the most up to date data, although the sample size is small.

This question is a potential minefield, among other things because: what does it mean for a community to "lean politically"? who exactly is the "community"? and even what exactly is "political"? (Notice that the answer to the last question is arguably itself political, so we have a recursion here.) There is the soft ban on politics, but debating the meta aspects of this question is already, kinda, debating politics.

Ok, let's try anyway:

The short version is that LW is not about politics, and political debate is usually discouraged, because most of us come here for smart interaction, and political debates tend to make us... well, not the most rational version of ourselves.

That said, of course individual people usually have political opinions. And there were a few surveys. Rafael already linked the most recent one, but I would like to direct you towards this detailed analysis of the 2016 survey with ~3000 respondents: part 1, part 2, part 3, and part 4 including politics.

Methodological nitpicking: The exact results may depend on whether you define the "community" as widely as "whoever reads LW, even if they never write a comment" or as narrowly as "has dozen highly upvoted posts on LW". It is quite possible that some political opinions may correlate with greater activity on LW; the narrowest definition will emphasize idiosyncratic opinions of the most prolific writers, while the widest one will resemble the general population. (So it could happen that most readers are X, most comments are written by Y, and most articles are written by Z.) Despite using the same labels, the political opinions in this community will probably be somewhat smarter and more contrarian versions of what can be found in the wild.

But statistics alone does not tell us how people with different political opinions interact with each other. There are places on internet where a difference in opinion naturally leads to purges: one group succeeds to appoint their members as moderators, and what started as 60:40 in year N becomes 95:5 in year N+3. This does not happen here. Maybe we are nicer than the internet on average. Maybe we are unorthodox enough to realize that a dictatorship of any political faction would sooner or later get us banned, too.

Some people believe that everything is political. From that perspective, LW would be political, too. (How could anything not be?) There is a consensus about some topics, for example that supernatural things do not exist. That already implies that religious people may feel uncomfortable here, and religion is often associated with politics. Refusal to be openly political can be interpreted as support of status quo. Refusal to ban people with minority opinions can be interpreted as their support. It is impossible to avoid being labeled as somehow covertly supporting a political agenda. We reject the label, though.

What is definitely discouraged is people coming here with the goal of debating politics. The fact that your first post was about politics is a red flag. If people who mostly write about other topics occassionally can't resist a political comment, it may be forgiven. But in general, political fighters are not welcome here.