Free advice is the best advice because having cost nothing and being unsolicited, it's easy to ignore. So here's my completely free advice to the Obama:
Responding directly to every bit of eejitry emanating from the McCain't campaign is not only impossible, because there is so much of it, but also counterproductive, because it is petty and juvenile. The McCain'ts are spoiled children on the school playground, trying to provoke a fight, so they can run, crying foul, to their parents who are blocking the school door to keep 'them' out.
It would be better to change the name of the McCain't campaign bus from "Straight Talk Express" to "Gutter Talk Unlimited." Every time a McCain't rant is aired, have someone, preferrably a John McCain't look alike, from your 'gutter talk' team take a nice graphical representation of the most appropriate McCain't virtue or value--the ones he wears on his chest: TRUTH, DIGNITY, HONOR, COURAGE, INTEGRITY, PROBITY, GOOD JUDGEMENT, EQUALITY, FREEDOM--crumple it up, throw it in the gutter, and stomp on it. Then have a child walking by pick it up and drop it in the garbage, while the McCain't continue fuming nearby. The voice over: "John McCain says, [fill in the blank, according to context]. But John McCain makes a mockery of what he says. Will the real John McCain reveal himself?"