Meanwhile, in Denmark:

Why have Danes turned against immigration?

...

In October the finance ministry, in its annual report on the issue, estimated that in 2018 immigrants from non-Western countries and their descendants drained from public finances a net 31bn kroner ($4.9bn), some 1.4% of GDP. Immigrants from Western countries, by contrast, contributed a net 7bn kroner (see chart). Data on immigration’s fiscal effects were what “changed the Social Democrats’ point of view”, says Torben Tranaes of the Danish Centre for Social Science Research.

Muslims are at the core of the issue. This year was the first time the ministry reported separately on the contributions by people from 24 Muslim countries. They account for 50% of the non-Westerners, but 77% of the drain. Alongside that worry are fears that Muslims bring notions about democracy and the role of women that Danes find threatening. Muslims are welcome, says Mr Tesfaye, but, “We can’t meet in the middle. It’s not half sharia and half the Danish constitution.”

...

https://archive.is/kXMi7

Heck, they could just make it easier for documented immigrants to live here.

The interesting thing is this is Spain's second wave of doing this, and the economic studies on the first wave of it showed visibly positive results. Spain's economy moved in growth, and with a size larger than many other European nations in similar background conditions of flat to negative population growth, but tighter immigration allowances.