Well, I agree with you, FreeReign. That's what the places where Rabs and I part ways. Rabs sees no difference between a Republican who betrays us on two or three important issues but is usually reliable vote for the GOP, and a Republican who betrays us on dozens of major issues and votes with the Dems more often than us. Rabs himself said the degree of treason makes no difference to him, he thinks anyone who votes the wrong way on an important issue must be purged from Government.
Of course I disagree. Someone like McCain should be opposed in the primary because they stabbed us in the back, but when the general election rolls around, McCain is clearly better than a full fledged marxist RAT. McCain is still more conservative than any AZ RAT. The same is not true of someone like Scozzafava. Not only does she need to be stopped in the primary, but she is unacceptable in the general election as well. Scozzafava is so liberal she's to left of many Dems in NY, and is even running to the left of the Dem nominee for this Congressional race (again, not to say he's conservative -- they're both liberals, but DailyKos likes her better) Someone like Scozzafava needs to be opposed in the general election too, because the only thing electing them will accomplish is helping Obama and Pelosi further their agenda most of the time.
Now the fact Rabs is wrong about McCain doesn't change the fact he's 100% CORRECT about socialist RINOs who side with the Dems most of the time. These kinds of "Republicans" MUST be opposed any time they seek office, regardless of whether they're running in a "blue state" or "blue district". I applaud Rabs for speaking out against liberal activists like Scozzafava.
Except that McCain is not your garden-variety RINO; McCain is a super-RINO who does not just passively oppose conservatives (by voting against them) but actively opposes them on a number of issues (immigration and cap-and-trade are by far the worst) by taking "nation-killer" positions and bringing legislation forward that furthers leftist goals. Furthermore, McCain is actively engaged in recruiting and training more RINOs to become like him (note that Graham's foray into cap-and-tax was inspired by McCain) by endorsing and supporting them (e.g., Crist, Specter before he defected, Kirk, Whitman).
In the short term, yes, McCain is certainly preferable to practically every Democrat out there. However, in the long term, McCain does immense and potentially irreparable damage to the conservative cause by attacking what is supposed to be its primary political vehicle--the Republican Party--from within. And, in that sense, McCain, in the long term, is far worse than any Democrat.