The usual ones come to mind first - Veritasium, vsauce, CGP Grey, etc...the big names that I expect other people have suggested. So I'll try to suggest some others.
Kurzgesagt - In a Nutshell has lots of well made videos on science, politics, ethics, medicine, etc, etc:
https://www.youtube.com/user/Kurzgesagt/videos
It's Okay To Be Smart is similar but more focused on science:
https://www.youtube.com/user/itsokaytobesmart/videos
Second Thought has some interesting short (~6 min) videos you might find useful for a topic:
https://www.youtube.com/channel/UCJm2TgUqtK1_NLBrjNQ1P-w/featured
Alternate History Hub has videos speculating about how things might be different if events in the past had happened differently. Might be relevant, depending on what subject is being taught in the classroom you mention:
https://www.youtube.com/user/AlternateHistoryHub/videos
Real Life Lore has a mix of videos, mainly focused on geography, economy and history. Some are direct answers to questions (e.g. How big can a tornado be on Earth?), others are interesting bits that could bring about discussions about politics, such as the series of videos on odd national borders like enclaves/exclaves (parts of one country inside another country) or an area that changes nationality every 6 months.
https://www.youtube.com/channel/UCP5tjEmvPItGyLhmjdwP7Ww/videos
It doesn't cover what I think might be the oddest national border though - Lake Constance and the non-existent borders between 3 countries. The national borders for each country end at the lake. It's not a trivial little pond - it covers well over 500 square kilometres. Which country owns which part of the lake? Nobody knows. More strangely, nobody cares. It's been like that for a long time and it works. So there's a possible topic for discussion - do we always need national borders?
I really very much like Historia Civilis, so I'll mention it even though it's a bit of a stretch for what you asked for. The videos on the ancient Roman political system might be of some relevance because they're well made short summaries of parts of a democracy very different to our own and that might promote discussion.
https://www.youtube.com/channel/UCv_vLHiWVBh_FR9vbeuiY-A
Jabzy's "Three Minute History" series covers a lot of things many people in this country won't have heard of and the videos are short (no surprise, given the title). You might find something relevant there:
https://www.youtube.com/user/JabzyJoe/videos