Sure Trump can win the Presidency unless he gets disgusted and drops out.
You better believe Tokyo Rove and his RINOs are looking high and low for dirt and mud to fling. Dittos for Hill and Bill.
I would like to think you are right that he can win as a Republican, but my fear is that his ego, and the highly-skilled ability of the Republicans to self-immolate might push Trump to go 3rd Party, at which point we can all start practicing saying, “Madame President” ...