Thomas Friedman, in the same column linked in the previous post, finds a lesson about immigration in the Scotland referendum result --
One reaction: I’m glad a majority of Scots rejected independence. Had they not, it would have clipped the wing of America’s most important wingman in the world: Britain. Another reaction: God bless America. We have many sources of strength, but today our greatest asset is our pluralism — our “E pluribus unum” — that out of many we’ve made one nation, with all the benefits that come from mixing cultures and all the strengths that come from being able to act together ... This is why America has such an advantage with its pluralism, and why — if Scots are brave enough to preserve theirs, and Spaniards are struggling to keep theirs and Iraqis are groping to find theirs — we should have the wisdom to pass an immigration reform bill that enriches ours.
Note the equation: Scotland on its own = lack of pluralism.
The above photo (BBC) is Glasgow native Peter Capaldi, the current Doctor Who. He was born in Glasgow. His mother was from Cavan and his father from Lazio. And there are lots of Italian-ancestry Scots and even more Irish-ancestry Scots. Scotland has always had immigration. Nor is their indication that an independent Scotland would have a more restrictive immigration policy than the UK -- in all likelihood, it would be less. There's no obvious link between how a nation treats migration and its willingness or lack thereof to be part of a bigger sovereign state.