A former Kansas State student who left the university and became the “right-hand guy” for the head of a white nationalist organization has stepped down as the treasurer of its foundation as its leader remains under federal investigation in connection with the Capitol insurrection. Jaden McNeil, whose offensive tweets in 2020 about the murder of George Floyd by a Minneapolis police officer propelled the school into the national spotlight, announced his move on the online messaging app Telegram. He said he would no longer be an officer of the America First Foundation, the nonprofit arm of far-ri…