Read this article.

She certainly sounds like she might be an "Obama-con."

Choosing Palin seeks to exploit the contradictions inherent in the Dems' campaign. So she is inexperienced. So is Obama. (Of course this is fallacious, but it doesn't have to be true to convince some people. It is what Hillary supporters were saying all year- about O.) 
So she is an unimpressive public speaker.
The Repubs have  presented this as a virtue all year, picking up on Hillary's crack about Obama's experience being a "speech in 2004."
She is unknown. Well, Hillary campaigned as a known quantity, in contrast to Obama.
McCain is simultaneously trying to blur boundaries between himself and Obama, while exploiting the fractures that emerged during the Democratic primaries.

Certainly McCain would have a better chance at winning if he only had to exploit the inherently divided Dem party. But faced with Obama, he cannot ignore the strength of the Democratic candidate. And he manifestly pales (pun intended, sorry) next to him, on the merits. So how will he try to win?
By being the underdog, the outsider, the anti-Establishment candidate. In other words, by playing Obama to Obama's Hillary.

In a memorable moment last month, Rep. Steve Cohen characterized Dick Cheney as a barnacle attached to the Constitution.
This was inspired by Addington's argument that Cheney was not in any particular branch of our Government, whose obligation is to check and balance one another, and so one of the core principles of U.S. Government taught routinely in civics classes simply did not apply to the likes of the Vice-President.
But barnacles are harmless organisms, attaching themselves benignly to the hulls of ships without causing damage.
I thought that the leech was a better characterization of the Addingtonesque individual, as leeches attach themselves to branches of the bloodstream and suck the blood from them.
But leeches have a long, distinguished history as medical tools, sucking harmful things like venom from a local wound.
The lamprey is the best fit at the moment, Not only is it exceptionally repulsive in appearance, it is a parasite that has never been part of the doctor's toolkit.

And we see (thanks to wikipedia) that the lamprey has always had a reputation for malevolence:

 

Vedius Pollio was punished by Augustus for attempting to feed a clumsy slave to the lampreys in his fishpond.

...one of his slaves had broken a crystal cup. Vedius ordered him to be seized and to be put to death in an unusual way. He ordered him to be thrown to the huge lampreys which he had in his fish pond. Who would not think he did this for display? Yet it was out of cruelty. The boy slipped from the captor’s hands and fled to Caesar’s feet asking nothing else other than a different way to die—he did not want to be eaten. Caesar was moved by the novelty of the cruelty and ordered him to be released, all the crystal cups to be broken before his eyes, and the fish pond to be filled in... – Seneca, On Anger, III