You make some good points, and I also know that there are some moderate Republicans supporting Dean right now. (I'll probably get flamed for saying it though.) I will say one thing for Dean--he's very articulate. That could give him an advantage.
There are really 7 types of voters, many overlap.
1. Near 100% Party loyalists. These people will vote GOP or Dem no matter what. Detroit and Ottawa County MI are the two extreme examples in my state.
2. Hard line conservatives or liberals. These are JUST as important as the 'moderates' that get all the hype. If you can't get your issues base to back you, that makes it that much harder to win. There are a LOT of these in my county. Liberal or moderate republicans can get as low as 53% here because conservatives won't vote for them. Conservative Republicans can get 70% or higher.
3. Reagan Democrats/Union Independents - Social Conservatices, economic populists. - These are a lot of the union members that don't drink the kool-aid. Macomb County, Monroe County, North Michigan. Those areas have a lot of them. They voted for Gore, but also for Posthumus. They hate wimps too. Gephardt would do well with them. Kerry would NOT.
4. Soccer Moms - Security is key, but personality is the biggest factor. They've leaned democrat recently. Very unpredictable and unreliable voters IMO.
5. The wallet - Most common non loyalist voter. Very politically uninformed. If money is good, keep them there. If not, throw the bums out. Gore did best among these independents. Posthumus did well among wallet voters here for the same reason.(Those that liked Engler usually voted for him too) These scare me the most right now.
6. Single Issue - Ties to the base to some extent. Guns, Abortion, Taxes, NAFTA, GATT, Drugs, Immigration.
7. Small l libertarians. - These tend to vote for the more pro-freedom candidate. Largely tied to single issues, but there are several issues tied together.
Dean may do very well among the wallets(Doesn't matter if it's Bush's fault or not), small l libertarians(Patriot Act, Dean's friendly REPUTATION on guns, outsider).
Gephart is probably the 2nd strongest of the dems and could be a tough race with labor united.
Kerry is Dukakis. Can you see him in a tank..... He may do well with sucker moms, but I bet he'll get 30% of the guy vote, maybe 15% among white guys that don't live in New England or San Francisco.