I agree with what you said except for Ohio and Florida. In the next presidental election, Obama will nit be running so the black turnout will be lower. So for 2016, both states lean Republican and if Jeb wins.the Republican nomination, Florida will be a given.
It is the increasing Latino vote, not the black vote that is my primary concern. If Hillary Clinton is the Democrat nominee, the increase in the liberal women’s vote will offset any decrease in the black vote.
But yes, I agree that it might take a different Democrat more than 14 states to reach 270.