They're playing the same game the NAACP did in the 20's and 30's -- surging their surplus population into Northern cities where political clout is available, leverage over the federal government.
Moslem countries have surplus population and the Saudis are using mosques as welcoming committees and rabat centers -- rallying points -- for their Moslem emigrants into the West.
It takes pressure off regimes in the extant umma (Moslem world) and transfers it to the West.
I tried to post this yesterday but my browser locked up...
The Saudis have been funding the expansion of wahhabism in the West since the seizure of Mecca in the 1970s.
The Saudis play both sides of the coin, they are perfectly willing to export radical islam but they want help from the West to keep it tempered down “at home in SA”.