Why would a country on the right allow and invasion of refugees from countries on the left?
The combination of "secular-rational values" and "self-expression values" results in an effectively-zero birthrate. (So does neutral to "secular-rational" values combined with a recent history of Communism, creating the bubble your chart identifies as "Orthodox.")
The "rationalist," wondering how economically to sustain his "self-expression," fixes on "traditionalist" immigration as an option. It wasn't a bad theory ... might have worked ... but the experiment has been run and the results are not what was hoped. The "Orthodox" bubble, having had its economies nuked by Communism, had little to offer immigrants until those countries became the EU gateway to Northwestern Europe's welfare paradises.
The wealthy elite and political leftists hate the nation-state, especially conservative ones like the US has historically been, so they strive to replace the native voters with poorly-educated, low IQ, and culturally-misaligned foreigners who will end up on the .gov dole. These types are easily manipulated into voting for more government and for trashing the constitution.