The Left have championed mass immigration in the post-World War II period because they see it as changing the political landscape so that Leftist parties will eventually never be dislodged, and elections rendered more useless than they are now. Witness the following gloating:
https://www.breitbart.com/politics/2019/11/10/ny-times-tidal-wave-mass-immigration-hands-virginia-democrats/
“A “tidal wave” of mass immigration has “tilt(ed) the field toward the Democrats” in the state of Virginia, the New York Times admits. Last week, Democrats took control of Virginia’s House of Delegates and the State Senate. Now, the Democrats hold power over the state’s legislature, the governor’s seat and the lieutenant governor’s seat — the first time since 1993 that this has occurred. The New York Times now admits that four to five decades of mass immigration — where about 1.2 million legal immigrants are admitted to the United States every year — has shifted Virginia into a blue state: Not long ago, this rolling green stretch of Northern Virginia was farmland. Most people who could vote had grown up here. And when they did, they usually chose Republicans. [Emphasis added] The fields of Loudoun County are disappearing. In their place is row upon row of cookie-cutter townhouses, clipped lawns and cul-de-sacs — a suburban landscape for as far as the eye can see. Unlike three decades ago, the residents are often from other places, like India and Korea. And when they vote, it is often for Democrats. [Emphasis added]
…
“It’s a totally different world,” said Charles Poland, 85, a retired history professor whose family has lived in Loudoun County for four generations. His family farm is now dotted with subdivisions filled with four and five-bedroom homes that sell for $750,000. The family legacy is a road named Poland. “If my parents came back today, they wouldn’t recognize the place. The changes came like a tidal wave.”
The goal is now in sight for the Left of transforming the West into a multicultural dictatorship. Immigration was but one of the many weapons used to bury the traditional West.