It is true that most Republicans in 1964 held vastly more liberal positions on civil rights than Goldwater. This strikes Williamson as proof of the idiosyncratic and isolated quality of Goldwater’s civil rights stance. What it actually shows is that conservatives had not yet gained control of the Republican Party.
But conservative Republicans — those represented politically by Goldwater, and intellectually by William F. Buckley and National Review — did oppose the civil rights movement. Buckley wrote frankly about his endorsement of white supremacy: “the White community in the South is entitled to take such measures as are necessary to prevail, politically and culturally, in areas in which it does not predominate numerically.” More often conservatives argued on grounds of states’ rights, or freedom of property, or that civil rights leaders were annoying hypocrites, or that they had undermined respect for the law.
The Conservative Fantasy History of Civil Rights -- Daily Intelligencer