Well to varying degrees most westerns having been saying that for decades.
Perhaps, but that's why immigration has been such a hot button issue. There are very few people (if any) who have been arguing for a complete moratorium on immigration. Likewise, there are very few people (if any) who are arguing for completely open and unchecked immigration. Most of the debate (and this is why it's an "elephant in the room") seems to revolve around which immigrant groups are "acceptable" and which ones aren't. The so-called "race card" gets thrown around quite frequently as well, further complicating the debate.