Electoral College: How It Works in Contemporary Presidential Elections [May 15, 2017] [open pdf - 916KB]
"When Americans vote for a President and Vice President, they are actually choosing presidential electors, known collectively as the electoral college. It is these officials who choose the President and Vice President of the United States. The complex elements comprising the electoral college system are responsible for election of the President and Vice President. The 2016 presidential contest was noteworthy for the first 'simultaneous' occurrence in presidential election history of four rarely occurring electoral college eventualities. These included (1) the election of a President and Vice President who received fewer popular votes than their major opponents; (2) the actions of seven 'faithless electors,' who voted for candidates other than those to whom they were pledged; (3) the split allocation of electoral votes in Maine, which uses the district system to allocate electors; and (4) objections to electoral votes at the joint session of Congress to count the votes. These events are examined in detail in the body of this report."
CRS Report for Congress, RL32611
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html