I see.

Well, foreign intervention and propaganda in democracies is nothing new. It is well documented all the way back to the time of ancient Greece.

So your contention is that in Germany and perhaps other countries (France?) some of the most popular political parties are popular only because their partisans are uneducated dupes or worse, in thrall to foreign powers. Perhaps you would be better off ideologically not supporting democracy - it sounds like it is not for you. Of course democracy has its problems - and people voting for dumb ideas is one of them!

You can either accept that it's your duty to convince your citizens you are right to win their votes, or you can insist that everyone else is wrong and democracy means they should shut up and vote only the "right" way in accordance with establishment approved opinions and go about what Europe has been doing, which is to continue to pursue unpopular policies and blame Russiia/nazis/America/the Internet/free speech for their problems.

European center and left parties could suck all the oxygen out of the room and starve the far-right overnight if they simply introduced and enforced major immigration restrictions - but it's precisely this which is not a Establishment Approved Idea and deemed Unthinkable Hate. Democracy, as long as your opinions are allowed.