Let’s pretend the truth is that Trump offered a job in exchange for Carson’s endorsement.
If that’s true, why would Carson tell people this knowing or should have known this is illegal?
Is Carson an idiot or he is just trying to sabotage Trump?
Well yeah.......Ben's running for President would be the same as Trump going into Ben's operating room to do brain surgery. He wouldn't have a clue about the instruments to use or avoid nor the procedures.
Another answer is to look at the statements that were made during the endorsement.
Carson and Trump both indicated that Carson would provide advice on education policy. This is not a quid pro quo, it is Trump agreeing that Carson could help him with the education platform for his contest.
Later? Sec of Education? Well, that could be because he helped write the position.
This keeps everything above board. Done this way it is not a problem
The man’s a neurosurgeon, clearly not an idiot. He is however a political neophyte.