Quoting: YANTA, Post #86
"Vyacheslav Postavnin was quoted yesterday as saying that it was a good idea to keep the numbers of non-Russians in any given region below 20 per cent of the overall population. "If the norm is exceeded, it will make the indigenous population feel uncomfortable. As a rule people who come to such districts do not assimilate. They begin living by their own rules," he said.
I’m not sure that you understand this statement correctly. It is need to read 20% foreigners. Russians means citizens of Russia, not nationality.
Russia for several ages has Muslim population. Estimating in 20% might be close to a real figure. Part of it in Central Russia, other part of them is in Caucasus. Both minorities were always lived there. At Soviet time we ended up with Muslims form ex-Soviet republic. After Soviet Union collapse we ended up with new wave of migrants. Azeri kicked out Armenians fro Azerbaijan, same Armenians did to Azeri people, but most of them moved to Russia rather than to their motherland. Russians were kicked out from new self pride republics. As you see situation is very complicated. Already society is stressed and these limitation are rather good than bad.