Varieties of criticism
Conservative criticism has nothing much to do with "left-wing" or "right-wing", because left-wing people are often very conservative, in the defined sense, while right-wing people can also be very radical, in the defined sense. The difference between "radical" and "conservative" has more to do with the belief in whether "a change to something genuinely new" is really possible and necessary. Radicals typically believe strongly that such change is highly desirable and necessary, and that it can be achieved. Their criticism is that there is "not enough" change. Conservative critics, by contrast, are very skeptical about any such change, because they feel the change is really "just another form" of something that already exists.
Open–closed political spectrum
Opposition to immigration is one of the starkest divides between open and closed parties. The closed position supports restrictions on migration, and prefers that immigrants integrate into the national culture. By contrast, the open position takes a more liberal stance on migration, and tolerates or even celebrates multiculturalism. Both left-wing and right-wing parties can be closed on the topic of immigration: the conservative Polish Law and Justice accuses immigrants of undermining Polish values and bringing in terrorists, while the socialist German Left Party considers immigrants a drain on the welfare state. Conversely, in the United Kingdom for example the Adam Smith Institute (a neoliberal right-wing organisation) and Vince Cable (a left-wing social democrat and former business secretary) stand together as some of the strongest defenders of immigration.