How popular is Sarah Palin? So popular that she's almost as well regarded as the original baller, Dick Cheney, at the time he was rolled out as the Republican VP nominee in 2000.

There are three fresh favorability polls on Sarah Palin that were conducted in whole or on part since her speech to the Republican Convention on Wednesday. These are from Rasmussen, ABC News and Diageo/Hotline, respectively. On average between these three polls, Palin is regarded favorably by 50.3 percent of voters, and unfavorably by 33.0 percent of voters, for a net score of +17.3:

Palin (2008)

Poll Date Fav Unfav
========================================
Rasmussen 9/4/08 58 37 (+19)
ABC News 9/4/08 50 37 (+13)
Hotline 9/4/08 43 25 (+18)
==========================================
AVERAGE 50.3 33.0 (+17.3)





PollingReport.com

Cheney (2000)

Poll Date Fav Unfav
========================================
NBC/WSJ 8/3/00 46 17 (+29)
Fox 8/10/00 53 17 (+36)
Gallup 8/5/00 44 22 (+22)
Time/CNN 8/??/00 43 18 (+25)
=======================================
AVERAGE 46.5 18.5 (+28.0)


Lieberman (2000)

Poll Date Fav Unfav
========================================
Gallup 8/19/00 55 13 (+42)
Fox 8/10/00 48 10 (+38)
NBC/WSJ 8/??/00 40 11 (+29)
CNN 8/10/00 37 14 (+23)
=========================================
AVERAGE 45.0 12.0 (+33.0)




Edwards (2004)

Poll Date Fav Unfav
========================================
Gallup 8/1/04 59 27 (+22)
CBS 8/1/04 35 18 (+17)
Pew 8/8/04 58 24 (+34)
Newsweek 7/30/04 52 28 (+24)
Time 8/5/04 48 20 (+28)
Annenberg 8/5/04 44 27 (+17)
Fox 8/4/04 51 28 (+23)
=========================================
AVERAGE 49.6 24.6 (+25.0)


Biden (2008)

Poll Date Fav Unfav
========================================
Rasmussen 8/23/08 48 34 (+14)
ABC News 9/4/08 54 30 (+24)
Hotline 9/4/08 42 29 (+13)
==========================================
AVERAGE 48.0 31.0 (+17.0)

Why have these past VP candidates gotten such strong favorability scores? It stems from the do-no-harm rule. The conventional wisdom is that a VP pick is more likely to be a reason to vote against a candidate than a reason to vote for him, making it unusual to select one who will trigger the strong reactions that Palin or Biden do.

Palin is probably an exception to that rule in both directions. I think she will turn out votes for John McCain. The impressive number is not so much her favorable ratings but the proportion of those that are strong favorables: 40 percent of Rasmussen's respondents, and 33 percent of ABC's, said they had a strongly favorable view of Palin. This is unusual for a VP nominee.

But, Palin will also lose votes for McCain -- and it's not clear that the losses won't outweigh the gains. Remember, favorability ratings should play into the strengths of a politician like Sarah Palin, who is charming and telegenic. But liking someone is not the same thing as wanting to vote for them; I have a very favorable view of my friend Eric, but wouldn't want his fingers anywhere near the nuclear trigger. And on preparedness measures, Palin polls unusually poorly: by a 42-50 margin (-8), voters in the ABC poll did not think she has the right experience to serve effectively as President; Biden's rating is 66-21 (+43).

--Nate Silver