As a Progressive who donated to Bernie Sanders on the day of his announcement, I found the Sanders interview that Steve Sailer recently posted to be quite interesting. It shows that, in principle at least, any real socialist really ought to support a much more carefully selective immigration policy than we have seen in recent decades.The current US immigration policy was crafted in an era when US had its first Catholic president who seemed intent on acting like a bad caricature of the fears of Conservative Protestants.
Catholics were an essential constituency of the Democratic party. That reality has changed. Catholics are now evenly split between the GOP and Democrats. There is simply no need for a Democratic politician to pander to the desires of the Catholic hierarchy to prop up their numbers in the US.
Milton Friedman pointed out that you simply cannot have a welfare state and open borders. For a long time, leftists like A. Phillip Randolph and Barbara Jordan (both black) seemed to intuitively understand that point.
I think to understand what changed you need to look at the evolution of the Left. The big policy win the Left had was the substantial adoption of the 1932 Socialist Party Platform constructed by Norman Thomas and Maynard Krueger and later borrowed by FDR's "Brain Trust". The Research Team of the Socialist Party, under the leadership of Maynard Krueger at the University of Chicago, had laid these policies out and showed financing was feasible. All FDR's team had to do was strip the plan of policies like direct taxation of concentrations of asset and Land Values, and run with what remained.
FDR's team did not have to deal with immigration issues because the Republicans had already greatly restricted immigration in the 1920s, which indirectly greatly strengthened trade unions.
Another distinct line of Socialist thought from the University of Chicago is influencing the policies of the modern Democratic party: Hillary Clinton and Barack Obama were both pretty clearly influenced by Saul Alinsky, a major figure in "community organizing".
Many Alinsky students were in turn influenced by the Cultural Marxism of Italian Antonio Gramsci. That line of thought puts a lot of emphasis on achieving cultural goals even to the abandonment of economic goals (and thus side-stepping the need to address limitations in Soviet-style economic planning that sent others back to their drawing boards). Alinsky explicitly told his students to do whatever it took to get and keep power.
I believe Sanders is much more influenced by Maynard Krueger and similar thinkers whose approach is more one of broad social engineering and obtaining of clear economic results. When I attended the University of Chicago, I took Political Order and Change from Maynard Krueger in the Fall of 1976 and Winter of 1977. I have not yet gotten confirmation that Sanders was a Krueger student, but their ideas on many topics are quite similar. They are both very pragmatic socialists willing to consider policies outside the socialist orthodoxy and both have very real concern with economic issues facing working Americans. Krueger freely admitted that some policies he had fought hard for, like public housing, did not have the results he hoped for and he encouraged his students to do the hard work necessary to create policies that would work.
National Review has recently been whining that Sanders is somehow not playing fair by adopting stands on trade similar to Pat Buchanan, Warren Buffett and Donald Trump [Bernie’s Strange Brew of Nationalism and Socialism, by Kevin Williamson, July 20, 2015]. It is true that balanced trade is not a traditional European Socialist policy. However, many Americans skeptical of concentration of wealth and power have taken similar stands over the years: Bernie is really just entering the mainstream of American thought on that point, staying in the realm of Krueger's pragmatic socialism, and returning to old Left roots.
It is really a fairly small intellectual jump from protecting markets via trade barriers to protecting markets via more carefully selective immigration policies. Both policies simply require that one understand that world labor markets are much less favorable to workers than US labor markets. Even some Communist Parties have adopted restrictionist immigration policies at times out of the practical necessity to preserve wages in more developed countries.
Sanders and his staff, like that of Dennis Kucinich, have been quite sensitive to the issues presented by high tech guest worker visas like H-1b and L-1a programs. But I do not think he or his staff have quite thought through a coherent immigration policy. If they do, it will need to be focused on maintaining wage levels and giving all Americans more equal input into the process of selecting immigrants. If Sanders proceeds with his proposed debate with Ted Cruz, I expect he will be pressed on this issue. He will be further pressed if the GOP nominates a non-establishment candidate like Trump or Santorum.
If the race is say Sanders/Warren vs. Trump/Carson, trade may be largely off the table. Trump also seems little enamored with endless wars for Israel and Big Oil.
A few years ago, Trump was "liberal on healthcare". Once he has the nomination, it may be expedient for him to return to that stand, which will largely take health care out of the debate. Sanders will need to match Trump's proposal to tax concentrations of assets (which are a watered-down versions of Georgist policies FDR rejected from the Socialist platform). Sanders will be offering rural working whites some substantial New Deal-style programs (like free college tuition) while Trump is offering an immigration policy that at least represents their rhetorical concerns and a tax policy that focuses more on the uber rich than anything proposed in recent decades .
A lot of working class rural whites have not felt entirely welcome in modern academic institutions, so they may feel voting for immigration restriction is more in their interest. If the election is at all close, I fully expect these immigration issues will be gut wrenching for Sanders and his staff.
Thom Hartmann, Vernon Briggs and myself are among the few Democrats who have tried to carefully address the realities on this issue. I hope for his sake Sanders considers carefully what we have said, because his election and claim to represent a cross section of working America may depend on it.
If he wakes up on just how badly mass, legal immigration is affecting wages in America, Sanders will put tighter restrictions and fines on illegal employers and illegal investors than any Republican or moderate Democrat.