[...] for most of the twentieth century, while the GOP was usually more conservative, especially on economic issues, than the Democrats, there was a great deal of ideological diversity within the two major parties. The Republican Party also had a liberal wing, just as the Democrats had a conservative wing.

[...]

[...] the GOP of the 1950s and 1960s often had a stronger civil rights record than the Democrats, because the Dems still had a large Southern component.

Into the 1960s, the Republicans often were stronger on civil liberties than Democrats as well. [...]