They haven't done anything to discourage it.
Exactly what would you suggest they do to discourage it? And haven't you been paying attention to the way "conservatives" have gone for the jugular of the few voices who have tried to reassure us that this is under control? Hugh Hewitt, Rush, Grassley, even Bush through Rove's comments.
It's not bad enough that we are doing the Dems a huge favor by trying to dig a deep divide between our conservative and moderate Senators, nope, we also have to give them the bonus of stabbing our actual conservatives in the back for them, too. That's the part that disturbs me the most, I didn't get involved in these Specter threads until I saw "conservatives" trashing folks Bush, Santorum and Frist. And folks here just keep getting worse by day.