FORT WORTH, Texas — Of the many developments from ex-Dallas Cowboys, “Herschel Walker: U.S. Senator” was not on the Jeopardy board when his NFL playing career finished in 1997. It’s one thing to be a campaigning political hopeful, and quite another to go full on “Marjorie Taylor Greene.” Walker, 60, has made his choice. Walker is attempting to pull a Craig James and go straight to the United States Senate. The Republicans are banking heavily on this race, and specifically Walker, to regain control of the Senate. Only one candidate has the full support of former President Donald J. Trump. On Tu…