This is because the U.S. has become so excessively politically polarized in recent years. The typical "conservative" here is more like the "extreme right" elsewhere around the world. They're literal "extremists", taking those political views to the furthest extremes they can think of, and actively hating anyone and anything that's not totally in line with that extremist viewpoint. (The political "left" has become much the same in the other direction here these days as well, thus exacerbating the issue from the "other side".) It's really not a "winning combination" for humanity in general. When (some) folks say "both sides are the same", I suspect that's what they're referring to. They're both becoming increasingly "extremist" in their respective viewpoints, and unwilling to move toward "the middle" even a tiny bit to allow for any productive discussion or compromise that could benefit everyone involved.