Simple - keep the pressure on Kerry to stand up for Democratic values, even controversial ones. If you think Edwards can actually take the nomination from Kerry, then stick with him. But otherwise, Edwards delegates won't be able to pressure Kerry for stronger stands the way Dean delegates will.
The problem that i and a lot of Democrats have with Kerry is that he's a finger-in-the-breeze politician, changing his story to match what he thinks voters want to hear. He may be talking an okay Dean-lite game now, but there is good reason to be afraid that he'll swing to the
right center as soon as the coast is clear. We're already seeing that with his wishy-washy non-endorsement endorsement of a Constitutional amendment to "define" marriage.
Even if Dean can't actually beat Kerry in the primaries, there's good reason to stay in. This is about the soul of the Democratic Party. The more delegates Dean can bring to the table, the more vertebrae we can give to Kerry to prop him up and make him stand for something other than getting himself elected.
Fall in love, but fall in line. Yeah, okay. The Democratic Party should be a big tent. But people like me should be invited in, not dragged in kicking and screaming. The best way to do that is for those of us who care about Democrats being for something rather than just against Bush walk into that tent with real muscle.
