[int_19h]

Holocaust denial (which is definitely politics, even though it's the despicable kind) is criminal in most of Europe: https://en.wikipedia.org/wiki/Legality_of_Holocaust_denial#B...

Some European states also ban left-wing political symbols: https://en.wikipedia.org/wiki/Bans_on_communist_symbols

[sgift]

None of that is jailing for a political belief. You mix beliefs and actions.

[int_19h]

It is an expression of political belief, which is what is normally meant in such contexts. I don't see much point in detangling the two, as belief that is not expressed is by definition something that you cannot act against since you don't know about it.