Populist Reform of the Democratic Party

You're saying just about what he said.

He started exploring a run well before he announced. However, my theory is that, like many here, he was waiting to see if Warren would run. When it became clear to him that she would not, he announced informally. That was sometime near the end of May.

He believes the US middle class will be gone in another generation unless something is done to "reverse the curse." (Red Sox fans will understand that term.) I think that's why he felt he had to run, even though he may have preferred not to.