Didn't he vote for Civil Rights though, or am I mistaking him for another Texas Republican.
There were two Republicans in Texas's House delegation at that time - Alger and Ed Foreman (guy from West Texas who served one term and later got elected in New Mexico). They both voted against the CRA. John Tower voted against it in the Senate.
George H. W. Bush voted for the Fair Housing Act and some other civil rights-related legislation when he was in Congress but other than him the Texas Republicans elected in that era were very anti-civil rights.