Very sneaky, Obama
Trump now calls him out for treason. I get what Barack is doing. As Hillary floundered, he uttered, "this old fuck would never have beaten me".. So now he will make it SEEM like Trump is running against Obama, not Biden.
As the Twitter war grows, trump can only be thankful Barack cant actually be on the trail.
(unless of course Trump is right about the actions of the former president while in office)