I hear you but in this case, I think the grass roots can overcome that. If so, it will be the first time the grass roots Republicans will have chosen the nominee since 1980.
There is no comparison between 1980 and 2008 or between Reagan and Thompson. Reagan was an established national political figure who nearly defeated a sitting President for the nomination in 1976. Reagan had an organization established and supporters ready early.
Thompson’s only real chance is the same as Newt’s — that the other candidates will crash and burn and there will be room for a relative newbie. That scenario has happened recently — on the ‘rat side. Republican nominations just don’t play out that way. Candidates have to pay their dues first — as Reagan, Nixon and GHWB did. (GWB had his Dad’s name and connections as well as lots of friends and supporters elsewhere).