Boris is far from being an idiot, but what he is is a buffoon, along the lines of the court jesters of mediæval times. They, too, could get away with saying outrageous things to their lords and masters, but they rarely if ever BECAME lords and masters themselves.
Thus, I believe his hopes of ever leading the Tories is doomed to failure. The incident referred to here enabled Cameron to make a joke about Boris "defying gravity", which could have referred either to the attraction of the earth OR seriousness.
On the other hand, if the Tories do make him leader, it won't be long before we become even more of a laughing-stock in the world.