The next time you’re engaged in a political discussion with someone who has very strong views different from your own, ask them if they can name two famous thinkers or politicians whose politics are opposed to theirs who they also think are very smart and genuinely concerned with making the world a better place. If they can’t, it’s not clear they are able to grant the good faith such discussions should have.
I'm stuck on the criteria of "genuinely concerned with making the world a better place". Sure, plenty of my political opponents want to make the world a better place, but they are domineering and even megalomaniacal about it. Basically, the way that they would make the world a better place is to force everyone else to conform to their own ethical and ideological system.
I can really only interpret "make the world a better place" as meaning "generally improve the welfare of humanity." There are plenty of people out there (including many Americans) who clearly indicate that they view vast swaths of humanity as their enemy, for no reason other than a difference in culture, values, or lifestyle. These people will identify someone as an enemy even if that person has never expressed any ill intent towards them, or acted in any way that is clearly harmful to others.
These people are commonly known as culture warriors. Some culture warriors only use the arsenal of cultural confrontation -- such as rhetoric. However, others think nothing of using violence (including the state). This later group ranges from the "Clash of Civilization" Islamophobes who want to bomb foreign countries back to the stone age and shut down mosques in America, to the Drug Warriors who intend to "scare straight" all of those hippies and ravers. These people clearly do not want to make the world a better place for people with different cultures. They explicitly intend to cripple others who pose no material threat to themselves.
The thing about these people is that their enemies list knows no bounds. We see that it is generally the same group of people who attack all of these different subcultural groups. In contemporary America, they are generally a particular type of Republican. They attack religions minorities, cultural minorities, political minorities. If many of these minorities are free from harassment in modern America, it is only because we have fought these bigots to a standstill or we have learned how to avoid their attention, and they have turned their attention to less powerful groups. However, if those less powerful groups weren't around to distract them, then they would again turn their hate towards the more established minorities.
So basically, I believe that these people want to destroy me. There is no excuse for their advocacy of policies such as imprisonment (or even fines) for things like drug use. People who do so are my enemy, and I cannot trust them. I can only have a good faith debate with them in the most abstract sense, but ultimately, for my self preservation and the preservation of everything I value, I must hide from them and undermine their agenda at every opportunity.