The headlines are about the broad polling reaction to Palin. But the most fascinating part of the first Rasmussen poll on the matter is how those who are currently undecided in the election feel. They, after all, are the votes both campaigns are trying to win over with their veep picks. The key data is in the cross-tabs, which have been missed in some of the coverage so far.

On the critical question, "With Palin As Vice-Presidential Nominee, Are You More Or Less Likely To Vote For McCain," there's a striking result. Among those already for McCain, 68 percent say it makes them more likely to vote for him; only 6 percent say less; and 23 percent said no impact. Among those already for Obama, Palin made only 9 percent of them more likely to switch to McCain, 59 percent less likely, and 30 percent said it would make no difference.

But among the critical undecideds, the Palin pick made only 6 percent more likely to vote for McCain; and it made 31 percent less likely to vote for him. 49 percent said it would have no impact, and 15 percent remained unsure. More to the point: among undecideds, 59 percent said Palin was unready to be president. Only 6 percent said she was. If the first criterion for any job is whether you're ready for it, this is a pretty major indictment of the first act of McCain's presidential leadership.

One other striking finding. If McCain thought he could present Palin as a moderate, he was wrong. A whopping 69 percent view her as conservative (37 percent as very conservative), and only 13 percent see her as moderate.

From this first snap-shot (and unsettled) impression, Palin has helped McCain among Republicans, left Democrats unfazed, but moved the undecideds against him quite sharply. I totally understand why.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.