Some thoughts I have:

• I agree that making connections and learning more about the World Federalism movement seems valuable, especially for people working in global governance from a longtermist perspective.
• I agree that achieving a federalist world government would potentially solve lots of coordination problems that contribute to x-risk while being less susceptible to especially bad world government lock-in problems (than other world government types)
• That said, I think I'm a bit pessimistic about the tractability of the end goal of achieving a federalist world government, since it seems like a political impossibility without a massive change in global dynamics (which could happen in response to a large war, global catastrophe, x-risk evident enough to create political will, etc.)
• I should note that WF orgs are working on relatively more tractable subgoals for now that seem like they might be valuable by themselves, like trying to set up a (consultative) UN Parliament or improving representation/democracy/transparency in other global institutions.
• I don't think the World Federalist Movement is larger now or more attractive than it was after WWII, and it's not clear to me that there's reason to believe it'll grow past that point. (Really unsure about this point though)

Interesting, thank you for this! I haven't read much on global governance, which is likely why I struggle to think of ideal structures for such institutions despite my strong belief in its necessity.

Two questions:

• To you, what suggests that it's  "recently been gaining traction?"
• More generally, I know some EA folk are connected with the Democracy Policy Network ... Does that kind of network seem orthogonal to global governing work? Or would a push for global governance be more likely to be separate from domestic policymaking networks?

I am not convinced federalism does much to mitigate risk of totalitarianism. I think there is tendency for power to get concentrated to the federal level, regardless of what legal documents say, and to achieve totalitarianism it should be enough to get power over armed forces, law enforcement and highest courts. 

The problem with federalism is that it perpetuates our system of competing nation states with their diverse law and economies. This competitive environment:

• is what keeps us funnelling resources into defense and offense, which could be better deployed elsewhere
• results in wars, borders, trade barriers and all the resources used to maintain them
• prevents us tackling global issues like global inequality, famine, pandemics, and the effects of climate change. 

A one world government system with global law and a single economy, as proposed by the likes of globalhumanparty.org, offers a systemic evolution that could resolve all these organisational issues (at least on paper!), but it would require long term (multi-generational) transitional support for which the EA movement seems unsuited.