Whether or not it was Nixon and friends acting like racists is secondary. Tons of individuals and institutions piled on because there was power and money in it for them.
My read is that your statement is incorrect, in that they were not simply 'acting like racists'. Instead, they were instituting racially motivated policies to combat the advances of the civil rights movement through the '60s. Plus ca change.
The difference is that racism is not a secondary motivator. Racism would be baked into the desire for power, as it would then be a desire to instill white supremacy.
You can say it’s secondary, but it’s a good answer to the question raised by the parent: “it would be very interesting to know the reasoning to start it.”