I was on the board of a nonprofit conservative business club. We did fine until it came to supporting candidates. We got around that by saying we were only supporting candidates who were members of our club. We thanked our members for stepping up to the plate and running for office. But on this board, with no controls, I don't think we could get away with supporting GWB, etc. and still maintain our nonprofit status.
The host performs its task of providing educational forums according to a theme (that's the non-profit's sole function vis a vis the IRS) and does not endorse the content expressed by invited guests.
I guarantee this will work.
But, there are downsides to non-profits. If I were Jim I would know both sides or, since going non-profit would appear to have many advantages, become thoroughly famliar with non-profit administration and regs by asking those among his friends and contacts who have done it before.