Here are Sarah Palin's daily approval numbers from the Daily Kos/Research 2000 tracking poll:
Approve Disapprove No Opinion
9/11: 52 35 13 +17
9/12: 51 37 12 +14
9/13: 49 40 11 +9
9/14: 47 42 11 +5
9/15: 47 43 10 +4
In the span of five days, Palin has gone from +17 to +4 -- a statistically significant shift. This includes the Gibson interview as well as the media's sudden focus late last week on the Palin/McCain lies. In comparison, Biden is at 48/32/20, Obama is at 54/38/8, and McCain is at 51/45/4.
So Palin may not be the least popular of the four -- McCain is, but she is certainly the least liked of the four candidates, and given that both Obama and Biden are at +16 favorability, McCain's +6 and and Palin's +4 point to a fundamental weakness that will likely play a role moving forward.
How about McCain in that time period?
Approve Disapprove No Opinion
9/11: 55 44 1 +11
9/12: 56 43 1 +13
9/13: 55 43 2 +12
9/14: 53 44 3 +9
9/15: 51 45 4 +6
Not as dramatic a collapse as Palin, but still bleeding some popularity from the media's sudden focus on the dishonorable campaign McCain has run.
http://www.dailykos.com/