Obama didn't blacklist them, the National Democratic Party did. Both Obama AND Hillary also pledged to abide by their ruling and not campaign in Florida and Michigan.
Those people didn’t do anything wrong, and they DO count in the election.
Those people elected the officials that moved their primary in violation of party rules.
Their vots do count in the general election, but the party makes it's own rules about the nomination of their own candidate.
For what it’s worth, Hillary saw that correctly and did the right thing by the people of Michigan and Florida.
So that's why she pledged not to campaign in Michigan and Florida and only changed her story after the fact?
see #37