First time I have seen those figures. If correct, then these numbers are the real story. An incumbent GOP Senator from Texas gets only 60% of the vote.
Texas Primary Results (absent the Politico/Karl Rove spin for Cornyn)
https://team1.sos.state.tx.us/enr/results/mar04_169_state.htm?x=0&y=200&id=196
Not really. Rick Perry only got 51% in the Texas GOP gubernatorial primary in 2010 against Hutchison and Medina, but still cruised to a comfortable double-digit win in November that year against the Democrat.