Dallas was LBJ’s backyard.
And he had a history of having rivals bumped off.
http://educationforum.ipbhost.com/topic/6005-did-lbj-order-the-murder-of-john-douglas-kinser/
It seems there is only one photo of LBJ being sworn in. One.
When there were several, as is befitting an historic event, there was one of the series where the mask slipped, and instead of appropriately somber, he looked rather pleased with himself.
Yet he had no connections to and no way to make Oswald do the deed.