Plato has basically nothing to do with modern politics.

You're going to laugh, but I'm absolutely serious here: if your objective is to understand modern politics, I would start with The Prince and the Communist Manifesto.

Both of these are short, written by extremely influential figures, written for non-academic audiences, and have some amount of relevancy to current political operations. They absolutely do not explain modern politics, but they are important foundational texts. Spend 20 hours on the manifesto; 2 hours to read and 18 hours of commentary and related topics. Avoid going deeper into the communist rabbit holes. stop there. Spend 30 hours on the prince; look for college level lectures. You can spend more than 30 if you like, but don't go for the self help guru dipshits, obviously.

Just keep in mind the target audences and the potential bias the two authors bring to the table.

After those two, I want you to read On Liberty and read up on John Locke's social contract theory. Those four works will get you a lot of milage.