“Our military is not an equal opportunity employer. We’re looking for the best of the best to do whatever. We’re not looking for different groups, social justice groups. We don’t want to single-handedly destroy our military from within,” --T. Tuberville
From the 17th Century through the 1950s American white supremacy depended on the explicit violent control of BIPOC, hence racially segregated armed forces. Naturally they weren't going to supply the internal enemy with access to advanced weaponry and military training.
After WWII more prescient capitalists like Truman understood that the stability of their exploitative regime depended on moving to more subtle, less visible means of control, which included racial integration. The revolutionary activities of BIPOC veterans after WWII suggests the old time supremacists weren't wrong to worry.
Plausibly Tuberville is looking forward to a future more like the good old days before the war -- the civil war.