Nyhan puts Palin's unfavorables in context:
If Palin is indeed considering running for president, it's worth noting just how unsuccessful she's been at building the necessary public profile. Since last year, I have been tracking her poll numbers relative to the most obvious comparison -- Hillary Clinton, another polarizing female politician. Clinton could never fully shed the high unfavorable ratings she acquired during her husband's presidency, but she worked hard to improve her image and maintained higher favorable ratings during the period before the Democratic primary campaign began in 2007. By contrast, Palin's ratings have been consistently worse during the comparable 2008-2011 period, and the gap between her and Hillary has widened dramatically in recent months (data from Gallup).
Her unfavorables are indeed impressive. They just reached a new high in CNN's poll of 56 percent. But what I'd note as well is that her favorables remain at 38 percent, which is obviously concentrated in the GOP base. The poll of polls puts it at 35 percent - again roughly the core GOP vote. Huckabee is more popular as a person among Republicans, according to Gallup, but when you combine star power and favorability in the GOP, Palin is very much in the running:
Vigilance, Smithers. Vigilance.