Obama will promote, or even raise, bizarre claims to discredit his opponents. He has done this before, to good effect. It is a more aggressive version of law school debating technique, which gives opponents a minor point that they go nuts on, eating up their debate time, while the debater cleans their clocks on more important points.
Obviously, only someone confident in a lead can afford such a strategy, but the guy is audacious. When the lead dwindles or disappears, such a person may be at sea, though--at least for a while.