Obama also had the Bushes on board, along with Cruz. I don’t think it was anything other than a courtesy. A mere senator would hardly be able to “legitimize” Obama via a shared plane ride, especially since his and the Bushes’ presence wasn’t reported on every news break.
Obama stoked the flames of cop-hatred, and encouraged the terrorists of black lives matter, until he succeeded in getting numerous officers murdered. Then he headed down to the memorial to urinate on the fallen officers’ coffins. Even Cornyn had the decency to shun him. A US TX senator, however, lent his presence to the grotesque spectacle.
Yes, it lent legitimacy. If the entire TX delegation had shunned Obama, it would have confirmed that they recognize his role in these murders. But you can never count on Cruz to stand against rank evil...at least not at the expense of a ride on AF1.