McCain needs something big to happen. Nothing big will happen if he attacks Obama directly; he has already used that ammo. So…
Look for him to bring up the Democratic Congress all night. He’ll say: “If Obama wins, the Democrats will have undivided control of the government…That Democratic Congress has been disasterous these last two years…We can’t have unchecked control right now.”
ThirtySomething 
He mentioned it once. But not nearly as much as I suspected. Oof.