At her peak, after the Republican convention, 59 percent of likely voters held an overall favorable opinion of Palin.
Now that's down to 46 percent, while 51 percent see her unfavorably. Majority disfavor is danger for any public figure; so is its intensity -- and an unusually large 40 percent have a "strongly" unfavorable opinion of Palin.
Men now divide about evenly on Palin, 51-46 percent favorable-unfavorable, down from 59-24 percent Sept. 7. Women, though, have gone from 58-33 percent then to 41-56 percent now, currently viewing her unfavorably by a 15-point margin.
Another group in which Palin's rating has fallen especially steeply is among mainline or nonevangelical white Protestants -- a 24-point drop, from 70 percent favorable in early September to 46 percent today.
This is the same usually pro-Republican group that has moved toward Obama, now supporting him by a 10-point margin, enough to counteract his shortfall among usually swing-voting white Catholics.
Palin's also lost ground on her main stake, the common touch -- a 10-point drop in the number who believe she "understands the problems of people like you." (Again, the decline has occurred disproportionately among women.)
And about six in 10 likely voters continue to say she lacks the experience to serve effectively as president. That doesn't help McCain, given the level of concerns about his age.
McCain's own favorability rating is positive (55 percent), albeit behind Obama's 63 percent. (Joe Biden's seen favorably by 59 percent.)
But there's a big intensity gap between the presidential candidates: Just 29 percent of likely voters have a strongly favorable impression of McCain compared with Obama's 47 percent.
This plays out among their own supporters: Among those who back Obama for president, 83 percent view him "very" favorably. McCain's "very favorable" rating among his own supporters is 60 percent -- 23 points lower.
A similar dynamic is reflected in their enthusiasm scores.
As noted, among Obama's supporters, 70 percent are "very" enthusiastic about his campaign; that compares to just 39 percent of McCain's supporters.
In the last two elections, high-level enthusiasm for President Bush peaked at 55 percent in 2004 and at 44 percent in 2000; for John Kerry in 2004 at 46 percent; and for Al Gore in 2000 at 41 percent. Obama's blows by them all.