Palindrone is a headfake. McCain should be the real target. No matter
what the GOP cheerleaders pretend, nobody has ever voted for VP. McCain wants us to
focus on the sideshow while he acts "presidential" and "above the
fray". Scratch that, he looks like a creepy sleazeball. But at least, he stays out of the line of fire. His ethical problems, his scandals, his lies, his record ... are all forgotten about.  The fact is, no matter how much we discredit Palin, it won't hurt John McCain!!

A great diary from Kos blogger, Shesk, put it this way: Palin is a play action pass.

Play Action Pass

Definition: A pass play where the quarterback fakes a handoff to a running back while he's dropping back to pass.
Examples: On a play-action pass, the quarterback hopes to fake the defenders into thinking the offense is going to run the ball. By doing so, he accomplish two things. He slows down the pass rush of the defense and he forces the defensive backs to make a decision between covering their assigned receiver or coming up to help stop the run.

....

To continue the analogy, the quarterback (the Republican Campaign) has faked us all into believing that Palin (the running back) has the ball, when it is McCain who is the intended pass receiver.  The Republican offense is playing along, with right wing talk radio and Fox news acting as if Sarah Palin has the ball.  The play is so well executed that even the game announcer (the media) thinks Palin has the ball.  And, as the definition notes, this accomplishes two things:  1) It is slowing down the attacks on McCain, and 2) it is forcing us to make the decision between covering McCain or stopping Palin.  And what are we doing?  We're all going after Palin! Meanwhile, McCain is wide open, ready to receive the pass and charge into the endzone!

...

In the case of the election, everybody is playing as if Palin has the ball.  PALIN DOES NOT HAVE THE BALL!  THEY'RE THROWING TO MCCAIN!  THEY'RE THROWING TO MCCAIN!

In election terms, this means, "Palin is not running for President!"  McCain is Running for President! Look at McCain!"

1.  Tell people that Palin's not running for President.  Sure, everybody knows it, but they are acting otherwise.  Hammer it and hammer it again: She is not the nominee.  Quayle was not the nominee.  Agnew was not the nominee.  She does not matter.  Stop looking at her.  When someone mentions her, reply that she is not the nominee, McCain is.

1.  Stop attacking Palin as a strategy:  She doesn't have the ball; McCain does.  Attack her in response to someone's mention of her, but quickly change the subject to the fact that she is not the nominee.

1.  Ramp up our attacks on McCain. 
   

Second, anyone going after Palin for the important experience she lacks had better be careful not to dismiss the value of the experiences she does have. Raising a large family and running a small state may not be sufficient qualifications to assume the Presidency. But we're not going to get far by minimizing those jobs, either. Here again, the McCain campaign may be hoping that Democrats – or the press – will come down too hard on Palin, and spark a backlash that turns her into a working mom's hero.

Third, and most important, voters don't need our help to figure this out. In the end, they'll be the best and toughest judge of whether or not Sarah Palin is ready. Back in 1988, the Dukakis campaign actually ran an ad against Dan Quayle. It didn't work, and wasn't necessary. In any case, Quayle had only himself to blame for falling flat on the national stage. By straining so hard to compare himself to JFK on the campaign trail, he practically wrote Bentsen's famous line for him.

The only caveat is that Palin can operate as a sort of stealth swiftboater. She can make scurrilous personal attacks and snipes, and left unanswered, could make Obama look weak. The only way I could see to counter that, is to swiftly, firmly swat down attacks, but then pivot: "But she's not the nominee. John McCain is the nominee." and then go after him and his record.