Don't vote for a letter of the alphabet. Vote for a philosophy. Vote for a Conservative.
As I was reading your post, I had the following thoughts:
1. One of the selling points of the Republican Party to some of the typical Democratic Party groups (Hispanics, Blacks) has been "Take another look at us, you have more in common with our conservative values than you do with democrats and their leftist values!"
If the Republicans select a Democratic-Lite candidate as their party's standard bearer, that very useful argument evaporates immediately.
2. Another argument the Republicans use when wooing black citizens is "Get off the plantation, the Democrats are just going to continue to promise that they care about your issues until they get your vote, then they are going to forget about you completely, until the next election, when they will repeat the process all over again."
If the Republican Party is going to move left, and to continue treating Social Conservatives and Pro-2nd Amendment Conservatives like the Democrats do their Black Voters, these Conservatives will likely "leave the plantation" as well.
If not this election, surely at some point in the near future.
3. A "My way or the Highway" approach by those who have convinced themselves that Rudy is the "only" Republican who can win in '08 is, IMHO, a bad decision on their part. Such an approach usually results in a stream of taillights fading into the distance.
Just some thoughts during this trying time for Conservatives.