EU country banning a popular political party?

There's no such thing as 'democracy'. There are different forms. There is liberal democracy and majoritarian democracy.

Majoritarian democracy says that a majority vote is sufficient to justify anything. So, the majoritarians say that even the reelection of a Nazi party that intends to continue Hitler's policies is legitimate if a mere majority votes for that party.

Liberal democrats say that tyranny by the majority is wrong, and that only those parties which recognise that fundamental rights cannot be voted away are legitimately democratic. For a liberal democrat, it is not democratic to pursue a policy that allows 51% of the population to kill, incarcerate, or otherwise deny the fundamental rights of the other 49%. Majoritarians think otherwise.

You are a majoritarian populist. Both majoritarianism and liberalism are forms of democracy. Most countries operate the liberal democratic model.

 The Nazi party also represented a strata of political opinion.

That depends on what Hamas plan to do and whether you're a liberal democrat or a majoritarian.

Well, a majoritarian will say they have the right to do it if a majority of people vote for them. It seems that you're a majoritarian, so you'll understand that.

Yeah, nothing went wrong the last time a far-right party held power in Germany, Squeaks. 

Ukraine is riddled with supporters of far right factions afaik and has been for many years . That didn’t stop the EU and the US pulling it out io Russias sphere of influence. Unless this new German party is proven to be a Nazi clone then the comparison is pointless .

Well, you would think that. You're a majoritarian populist.

A liberal democrat doesn't see a government that attacks fundamental rights (killing, incarcerating on a whim, etc.) as legitimate democracy. For a liberal democrat, the very purpose of democracy is to protect the weak from the strong. So, a government that kills or incarcerates, or otherwise denies fundamental rights to a minority is not a democratic government, even if a tyrannical majority voted for them. 'It's the will of the majority' is not a get-out-of-jail-free card for atrocities and fundamental abuse of basic rights.

That said, majoritarianism is still recognised as a form of democracy, albeit a very dubious one (from the viewpoint of a liberal democrat). You can support a far-right racist party like the AfD and still claim to be a democrat. Your problem is that those who oppose them and their foul far-right policies are also democrats.