We have no idea how the Tory membership will vote. It could very well be that they vote for the other candidate if, indeed, Boris gets through to the last 2.
Who knows? It's not worth speculating, we just won't know until the final vote has been counted.
I think Boris Johnson is an intelligent baffoon but he has a lot of support in his party so I think there must be more to him than we are seeing. His fellow conservatives obviously think he has what it takes to be leader so, if he does win the contest, it will be interesting to see how things pan out.