If Democrats and radical Republicans both support Palin, would that spell the end of the Republicans?

I wonder why people say that Democrats are afraid of Sarah Palin, she doesn't have the potential to win an election on a national scale. People think that Palin is more of a celebrity figure. By 2012, the Republicans will have a huge debate amongst themselves over who best would be the leader of their party and it seems like Sarah Palin is the one leading. If Democrats and loony Palin supporters got together and build enough of a support for Palin then it would mean the Republicans have met their Waterloo with no other choice but to have Palin on the ticket. Republicans would not want to alienate their base by picking Mike Huckabee or Mitt Romney. Her succession to the nomination will make the Republicans lose power and credibility, but this is all in theory of what the strategy tells me