[nativeit]

It’s not hard. Start a 501(c)3, ask for members to donate and/or pay dues, hold some annual conventions (paid for by vendors) to evangelize the broader mission(s) and recruit new members, hire lobbyists to pursue the collective interests of members, rinse/repeat.

[jjeaff]

Well, it's a little more complicated than that. For example, a 501c(3) has limited abilities to lobby or otherwise engage in politics.