Not sure. I am not intimately familiar with Dutch politics, but the Dutch strike me as "morally flexible," so they probably trend extremely liberal by American standards, in both the tradition and current definitions of the word.
Like many polities in Europe, there is a group that is extremely skeptical of uncontrolled immigration and the difficulties of integration of new arrivals and on the other those who see this as not a big problem.
On the other hand, there is one side that see environment concerns as a big deal and are willing to adopt some extreme measures to stop man-made global warming (and sea level rise; this country is called the "Nether" lands for a reason). and others that see that as not such a big problem or feel that the solutions are adopted have been extreme.
Those four groups are not entirely coincident. (There are some who are concerned about both uncontrolled immigration and are concerned about man-made global warning.)
The Netherlands have Proportional Representation, so extreme parties, if they reach a certain threshold, get a seat in the lower house.
The guy making the video is Dutch, and he says Wilders' party showed that they have as much difficulty governing the Netherlands as the other parties, so their support dropped.
