I don't buy Susan Estrich's argument. Look at recent history- the biggest margin any Presidential candidate can reasonably expect is +10 on election day. What's Obama? RCP has him +4 right now, Fivethirtyeight has +2, and we're still only in mid-July. It's hard to deny that Bush's actions have skewed from traditional conservative rhetoric, whether you think that's an inevitable consequence of electing conservatives is beside the point. I think many conservative-leaning people are looking at McCain and able to justify supporting him despite the last 8 years because he says he'll embrace the conservative principles that Bush pulled away from.