Recommend watching "The Man" by Rod Serling. About a black man becoming President of the U.S.
His pre-decessor dies unexpectedly in a building collapse. Next in line is the VP, however he declines the position due to his very poor health. Next you would think would be the Speaker of the House - they don't really mention why not him, but I think he had recently stepped down from that position and the new speaker had not been elected yet. So who get's it? The President Pro-temp.
Very interesting movie! James Earl Jones plays the President. Night and day difference in character than the black president we had in reality.