He was also quite the xenophobe, who deplored the mass influx of immigrants (codename for "Jews" in those days) into his native New England. Ironically, James would later be celebrated by a later generation of American writers and critics, who were predominantly descended from the Jewish and working-class Catholic immigrants he viewed as culturally backwards, while he was largely forgotten by the European literary establishment. There's a lesson to be learned there...
James was hugely influential on F.R. Leavis, Ezra Pound and T.S. Eliot and their idea of 'tradition'. A concept that Saul Bellow understood was meant to keep people like him out.
...after he forsook America and moved to Europe (England?).
What misplaced arrogance.
James wasn't a New England native. Was he really more anti-immigrant than other American Protestants of his day?
Wikipedia has an interesting article on James's book, The American Scene, which provoked such views:
The book as it stands has been praised and damned, respected and dismissed. The extreme reactions may result from the contradictions inherent in the book itself. To take maybe the most notorious example, James indulged in racist bashing of black people as incapable of alertness and attention, then praised the "most accomplished" W.E.B DuBois' The Souls of Black Folk as "the only Southern book of any distinction for many a year."
Similarly, James was full of misgivings about unrestricted immigration and its effect on America's already thinly stretched social fabric. (Of course, many Americans share similar doubts about immigration to this day.) But he conceded that the strong assimilative forces of American life would work on the children of the immigrants, "the younger generation who will fully profit, rise to the occasion, and enter into the privilege" of full citizenship.
James also constantly criticized the materialism and greed he saw all around him in American business. But he again admitted that the result was a huge increase in material well-being for the average person: "this immense, vivid general lift of poverty and general appreciation of the living unit's paying property in himself." It was in this widespread prosperity "that the picture seems most to clear and the way to jubilation most to open."
On the whole James doesn't sound so very different from any conflicted 21st century American. Indeed, he came from a very conflicted background: quite comfortable yet outside traditional American society.
Henry James's grandfather was a (Protestant) immigrant from Ireland who made a fortune in real estate, his father an international intellectual wanderer. Henry became devoted to England, but his brother was passionately American, and his sister a fiery partisan of Irish freedom. James probably isn't today's cup of tea, but he saw and understood more than most people in his day -- or ours did.
Was it so ironic that James was so popular with 20th century intellectuals of immigrant stock (particularly the Jewish "New York Intellectuals" of the "Partisan Review School")? He comes across as a 19th century "New York Intellectual" himself.