And as the last little exchange should have made clear, that's hardly a problem specific to the left or right of American politics. It's a symptom of the ridiculous, toxic, false dichotomy "us vs them" of modern American politics. And to a lesser degree, other similar western countries. The enshrinement of the two party system is the biggest issue in American political culture. Everyone believes their side is good, just and right about everything, and the other side is malicious, conniving and wrong or just lying. Those who think of themselves as left-wing will always seek to excuse, mitigate or explain away bad things "their" group does, and so will those who think of themselves as "part of the right". Because we're still just very clever monkeys, and we're programed to seek social groups, and protect and strengthen them whilst building our value in them, and because intentionally or not, the political system has tricked the majority of people into the belief that sharing a handful of political positions makes people a group. It's ridiculous. Sensible people should be able to recognise that a person can share political opinions with them, even share many opinions, without that person representing them and be perfectly willing and happy to condemn that person, and further they should be able to extend to others and recognise that two other people sharing opinions on some things doesn't mean they completely agree on everything. You can't judge any group by the extremists who not only believe in whatever philosophy, but also believe in their right or even responsibility to force everyone to believe as they do, or eliminate those who don't. Most Muslims aren't al-Qaeda, most Catholics aren't IRA, most left leaning people don't try to form separatist police free communes, most right leaning people don't plow cars into political rallies, etc.