The so-called conservatives are radical centrists at best. While today’s „far-right“ would have been considered moderate conservatives not so long ago.
And european mainstream right is no longer right for the last few decades on those topics. Today’s „far“ right sound like what mainstream right would say 10-20-30 years ago depending on exact country.
You said it yourself - even the right used to tolerate illegal immigration. But you were okay voting the center right at that time. And now you're voting the far right who are putting them in concentration camps. So you're far right, but you didn't used to be.
Here „far“ right offer is to deport illegals and curb new migration.
Also, we have detention centers since forever. What do you propose to do with illegal migrants waiting deportations instead? Put them in prisons? That's a wee to harsh, isn't it?
Of course, then people can start talking BS about muh concentration camps with allusions to soviet and nazi camps. But those camps had some specific features that ain't present in detention centers.
Just like it's not communism to advocate for better welfare, labor rights, affordable housing and so on.