Good article, but the author can relax a bit with the confidence that NEITHER Jeb nor Hillary are electable. Regarding Congress, it actually needs to be a check on BOTH the Executive and the USSC!
Unless the Democrats nominate Hillary and the Republicans nominate Jeb, in which case one or the other will be elected.
And no, Trump running as a third party candidate will not get elected. In a three party race, the best any third party candidate can hope for is to win a plurality of the electoral college, which means that it then goes to the House, which will pick the candidate of whichever party controls the House at the time.