I told my friend that I think people on the right are tougher, but he said that he didn't want to talk about politics.
Did you avoid talking about politics with him after that?
No.
If your friend said that he doesn't want to talk about politics, then continuing to try to talk about them is impolite. Not everyone likes to have political discussions, so when they tell you that they don't you should avoid talking about them. If you keep trying to talk politics with your friend then he might not want to be around you anymore.
Well I think most of the people that don't like talking about politics are liberal or socialist. It's fine to not agree with me.
If your friend feels uncomfortable you should stop. Politics are a heated issue and if you don't agree you might ruin your friendship for being too pushy.