The only thing Obama did was happen to be in the right place at the right time. The MoveOn people endorsed him, just like they endorsed Ned Lamont, so he won among elite Democrats who mostly have never done much of anything, so they don't know much of anything.
                He had the added benefit of being black, so that won him all the deep south states in the Democratic Party. He will probably lose those states in the general election, and he will probably lose the general election, just like Ned Lamont did.