It's been happening for a while among myself and the rest of the looney left, it's the right-of-centre governments (CDU, Tories, Ect.) who aren't changing their policies. Why? Because it benefits them.

Governments get to gradually eschew welfare because 1) too many people on welfare and 2) the majority, who are natives, won't fight to keep welfare laws up when they - correctly or not - feel like the only ones who are benefiting from them are workshy migrants. More migrants -> more welfare expenditure -> until a breaking point where the government announces that "cuts must be made" and "pension age must be higher. How about you all stop working at 70?".

At the same time, governments get another bonus - that is, weakened social cohesion. If you don't know and don't trust your Pakistani neighbour you're not going to take to the streets with the aforementioned neighbour and protest for anything at all. This is closely tied to the point above about welfare.

Also, governments get another bonus, which is a neverending circle jerk on immigration that is useful at election time: the right exploits it to get people angry, the left exploits it also, to feel morally superior and humanitarian. This polarizes the debate and gets people voting. Furthermore, governments get a built in scapegoat for anything that is going less than ideally in the country - lack of jobs, stagnating economy,small criminality, housing shortages,, etc., anything that should be resolved by a capable government suddenly has one single extremely convenient cause, that is, migrants. Double bonus. That's how you get governments that publicly denounce immigration as a crisis but don't do anything serious about it. They don't because they don't want to. They're playing both sides, the Right and the Left.

Eventually the average Joe and Joanne get shafted, with less rights, more competition, less welfare than pre mass migration and worsened social conditions. They get to deal with unsafe neighbourhoods and working until old age, while the rich and the powerful profit and holiday in Davos and Monaco.