I don't understand this war on the moderates

I've been hearing somewhat anecdotally how there's this movement to try to oust RINO's from the party. What's a RINO you ask, well the acronym should give it a way: (Republican in Name Only). How does one earn this label I still want to know because I'm not entirely sure I get it. But if I had to wager a guess, its tagged on anyone who dares vote against the party line, e.g. a moderate.

And the Democrats are not completely guilty either, although not nearly so as the Republicans right now. But I've heard that MoveOn wants to give a big financial push in supporting primary opposition candidates who are running against any "moderate" Democrat who dares vote against the health care bill.

Can someone please help me understand this? It makes no political sense to me. There's a reason we have moderates in Congress - because they represent moderate districts. If your party successfully ousts a moderate in the primaries with someone more ideologically "pure" - whatever that means, you are practically ensuring that you'll lose that district in the general election.

Run an extreme liberal against a moderate Republican in such a district, expect to see a Republican taking that seat for the next 2 years. And this runs even stronger if the economy remains in the doldrums in the 2010 election cycle - which it most assuredly will. Incumbents will naturally be in trouble in such conditions (fairly or not). So I suppose if you're running a more extreme candidate against a moderate incumbent, you have some chances of winning that seat. And I guess that's what the current Republican strategy is banking on. But its almost certainly not a sustainable strategy.

Get a voting record behind that less moderate candidate, and that protest vote that got her elected will turn against her just as fast.

What the Republicans are missing in spades is a viable message that resonates broadly as a viable alternative solution to what the Democrats are offering. They have become the protest party, the party of no. And until they figure this out, even if they succeed in picking up some seats in 2010 (with a big assist from a miserable economy) I have no idea how this is a long-term winning strategy.