Kos thinks that the evangelical Christian Right is imploding. He points to some schisms within, some stridency in their political claims (like that's new!), and some movement on the part of Republican politicians to distance themselves from the evangelicals.
I'll give Kos leeway for his political analysis. He knows way more about the strategies of political candidates than me, and if he says the Republican candidates are sucking up less to the evangelical Christians than before, I'll take his word for it. However, I know a thing or two about the religious right, and I would say that he's going way too far in saying that a little in-fighting, some crankiness, and some apocalyptic claims about the decline of politics adds up to an implosion.
From a scholarly perspective, there is some consensus around the quote by political scientist, Amy E. Black: “I’m sensing the emergence of an old guard and a new guard." This seems to be the case, where younger evangelicals are focused more on environmental issues and social issues like poverty.
What Kos implies, but is not the case, is that this generational split means that somehow people are becoming disillusioned with evangelicalism, or that evangelicals are becoming depoliticized in some way. You may even get a sense from reading his post that younger evangelicals are somehow pro-gay or pro-choice. None of this is true. Large numbers of people are joining evangelical churches, and there is no sign of decline. These next-generation churches are concerned with poverty and environment, but they are still very conservative on issues of sexuality and gender. And they intend to be political.
I don't know what this means for presidential elections, and I don't know whether this group will be a big factor in 2008. However, this is a very powerful network, with growing memberships, and as much political energy as ever. Just because there are new ideas in the mix doesn't mean they are going away.