I hope this helps. I'm not on the Conference Committee, but have an idea of how it works. Gary Glass may say more.
Thanks Jeff and Denny, you guys covered the major points.
We try to move the event around the country as much as we can, but we're definitely constrained by legal concerns, finding venues that will work for the event, and trying to keep hotel room rates reasonable for attendees. Denver was mentioned in this thread. In mid-to-late June, we'd be looking at room rates of $250+ in downtown Denver.
We look at the density of membership as well. A successful Homebrew Con is dependent on attendees bringing kegs of homebrew to share with fellow attendees. That means the venue must be within a reasonable driving distance for a large number of members.
The legal situation is tough one. With the significant up-front cost of Homebrew Con, we can't risk getting shut down by state alcohol beverage control. We don't gamble with our members money.
For Homebrew Con, we need to be able to serve unlicensed, untaxed, homemade alcohol-containing beverages along side licensed, taxed, alcohol-containing beverages. We also need our attendees to be able to transport multiple kegs of homebrew to the venue.
Getting laws changed isn't easy, but the AHA staff is here to help local efforts to update laws to allow for homebrew events, including Homebrew Con. Legislators in other states aren't going to respond well to someone from Boulder, Colorado telling them that their laws are bad. However, they are much more likely to work with their own constituents to pass sensible legislation that could help land an event like Homebrew Con that will generate millions in local revenue. We can help local homebrewers navigate the process of getting a bill passed, finding examples of other state laws that could be adapted to their state's alcohol code, etc.