Black voters support can make a huge difference.
As you note, Illinois could be close if significant numbers of blacks in the Chicago area voted for Trump.
There are huge numbers of blacks in Detroit who could tip Michigan.
The big black population of Atlanta could tip Georgia.
There’s a big black population in Philadelphia that could move Pennsylvania back to Trump.
That may well be true, however, how many of those votes will actually be credited to Trump AFTER the vote counters get done counting?
I live in lower peninsula Michigan and there are large numbers of black voters in the urban areas of Flint, Jackson, Battle Creek, Kalamazoo, Benton Harbor, St.Joseph, Grand Rapids, and Muskegon. I get a vibe that allegiances are shifting. It is reinforced every time President Trump visits Michigan to campaign.