They are using new social media tools to spread conspiracy theories that make people angry and afraid, and they capitalise on that anger and that fear.
But as they have risen in prominence, the backlash against them has also grown. As predicted, Liberal and Green parties were big winners, too. Their voters were mobilised by the far right - as well by their belief that the traditionally dominant parties can't cope with this new challenge, among many others.
Indeed, if there were real losers, they were the old centre-right Christian Democrat and centre-left Social Democrat parties, or at least those that have failed to catch the mood of the moment, adjust their use of social media and change their focus.
Those two parties used to dominate the European Parliament and thus European Union institutions. No more. Many now worry therefore about fragmentation, that we will end up with an EU that cannot take decisions because there are too many factions. But this is what's happening to politics everywhere. It's as true in the European Parliament as it is in many European countries.
In any case, there is an upside to this, too: The European Parliament will now be a place where real politics happen.
There will be deals to do, arguments to have. There are now issues, such as ecology and immigration, that command pan-European interest and require pan-European solutions - and Europeans seem to know it.
Not accidentally, voter turnout rose by double-digit percentages in Spain, Poland, Germany, Romania and Hungary, among others, as people realised that their votes actually mattered.
Not every country was having the same debates - far from it - but in every country the European aspect of the debate was important.
Despite itself, the continent is becoming a single political space.
The far-right in Italy copies tactics from the far-right in France.
The Greens in France watch the Greens in Germany.
Everyone watches everyone else's elections and uses them to prove points.
British Eurosceptics tweeted happily about the Gilets Jaunes protests in France, and French Europhiles in turn have mocked the Brexit crisis in Britain.
But in truth, nobody is "winning." Instead, politics is changing, very quickly, with new parties, new causes, new passions coming to dominate.
There may be a period when political institutions can't keep up, but eventually they will have to.
