Sure--in the primaries.
If you're advocating this in the general election, you're way off. Sometimes people forget that the rest of the world has a way of not getting our personal interpretations of our actions.
Anyone here who thinks that the Democrats taking over in 2006 will be read as ANYTHING other than proof that the Dems and their non-agenda are supported by the American people is either delusional or on something.
If Republicans know that nothing they do between the primaries and the general will cause them to lose votes from their base, they will have no reason not to stab their base in the back.
Your argument is somewhat analagous to a scene in The Maltese Falcon. Sam Spade informed some other characters that since he was the only one who knew where the Falcon was, they'd never find it if they killed him. One of them suggested that it would nonetheless be wise for him not to incite them too much, lest they kill him anyway.
If Republicans know that they'll lose if they betray their base, they won't betray their base. But the only way they can know that is if the base is willing to punish them for betrayal.