I found a lot of sites that cater towards talking about politicians and science. These ones appear to be somewhat active:

  Politics / Politicians
  - https://debatepolitics.com/
  - https://defendingthetruth.com/
  - https://www.houseofpolitics.com/
  - https://politicalhotwire.com/
  - https://www.politicsforum.org/forum/

  Science / Scientists
  - https://www.scienceforums.net/
  - https://thescienceforum.org/
  - https://www.physicsforums.com/
  - https://www.thenakedscientists.com/forum/
  - https://forum.cosmoquest.org/

Any decent online community will also have its share of memes. They are inevitable

Let me know if any of these hit the mark for you

Edit: Formatting