In regards to local police departments, a few big changes have been the degree of militarization in terms of training and equipment, significantly greater surveillance powers, larger and more active SWAT teams, and changes in search warrant requirements that basically allow the police to break into a house at will.
Just like with McCarthyism, if you're innocent you have nothing to worry about. Luckily, I'm a white, upper-middle-class guy with no accent, who's lucky enough to know a couple of cops and judges. So why should I care about the rights of some suspicious looking stranger? I guess that's the general attitude and that's how our rights slowly evaporate.