Protest parties will force EU rethink
Nigel Farage - leader of the anti-EU UKIP - is an astute political observer.
As the results began to come in from across the continent, he considered whether the increase in the number of Eurosceptic MEPs would change the way the European Parliament would work in the future.
"Whether that makes a big difference in European politics remains to be seen, but it's going to make a very big difference in domestic politics, particularly in the member states predominately in the north of Europe."
By European politics he meant Brussels, the parliament, and there's good reason to assume he is right on that score.
Despite the huge gains for anti-EU parties and those that wish to reduce the power of the EU, it's unlikely that the parliament will adopt a fundamentally different approach.
The main centre-right and left groupings still hold the majority of seats between them. Add in the Liberals and the Greens, and the parliament is overwhelmingly pro-EU.
The leading candidate for the EPP, the centre-right bloc which won this election, has said he wants to form a grand coalition with the centre-left S&D. That's to be expected.
The parliament is less confrontational than national elected bodies. The groups have to - and do - work together to pass complex legislation. There will be many moments in the coming five years when these four groups compromise with one another.
Then there's the fact that the anti-EU, anti-euro, anti-immigration parties who won last night are a disparate group.
Greece's left-wing Syriza will not find much common ground with France's right-wing National Front (FN). There is no anti-EU blocking minority to slow down business in the parliament. In the hugely important committees yes, perhaps, but not the plenary.
In that sense, if the main groups in the parliament choose to ignore those who didn't vote for them last night, they can.
National politicians however, can't afford to ignore them. That's where this election is likely to really shake things up.
In two of the three big national players in the EU, France and Britain, domestic politics is being shaped by the right wing, and especially the anti-immigration voices. Brussels has had to deal with an awkward UK for years on subjects like this. Not so with France, which has always spiritually been at the heart of the project.
But even before the votes had been cast, France's former president Nicolas Sarkozy - who many assume fancies a return to office - questioned some of the fundamentals of the union, saying the passport-free Schengen zone should be suspended, and that the EU should be stripped of some powers.
In Germany, the EU's biggest player, Chancellor Angela Merkel doesn't face anything like the same political pressure from anti-EU parties. Still, even in Berlin, they will be digesting the news that a sizeable part of the electorate voted for a new anti-euro party.
In smaller countries there are similar forces that will require the mainstream to take a good look at what voters are saying about their country's place in the EU. In each there are different forces at play, but in Denmark, Spain, Greece and elsewhere large parts of the electorate are asking for a rethink on their relationship with Brussels.
This will have an impact not just on domestic politics, but on the national leaders when they meet in Brussels at the European Council - where their job is to shape the direction of the EU.
Will that change the direction? Too early to say, but last night Nigel Farage concluded that "up until now European integration always seemed to be inevitable."
"I think that inevitability ended tonight."