Obama should be highlighting both himself and McCain. The campaign as it is now unfolding covers the former. The following delineates how he might approach the latter. BOTH are important.
McCain should not be able to troll for attention by launching a string of scurrilous ads in an attempt to see which stick(s), without response. This is particularly so since his own vulnerabilities are so stark. Talk about arrogance: Tossing stones from behind a 90+ percent glass "cover".