The Republican party thought she'd be a good VP. They might think it's a big enough block to make it worth it.
Are you paying the least bit of attention?
First of all, Palin was not chosen by a vote of all Republicans. To suggest she would have been the top choice for the party is ludicrous. They embraced her at first, but support is dropping like a rock.
Many see her as an embarrassment to the GOP, and many of its own members are going to lay the blame at her feet if McCain loses. The religious right will still love her, sure, but they hardly make up the majority of the GOP.
And to top it off, many conservative pundits are disowning the McCain campaign with the choice of Palin being the main reason.
I see a very tenuous relationship between mainstream conservatives and Palin. I see them cutting her loose once the election is over.