Missouri gained statehood in August 1821. A Midwestern state bordering the south, Missouri has, until recently, been a true battleground state with amazing historical accuracy at voting for the ultimate election winner. From 1904 through 2004, Missourians got it wrong just once – preferring Adlai Stevenson over Dwight Eisenhower in 1956. In 2008, the streak ended when Barack Obama lost to John McCain by the slenderest of margins, 49.4% to 49.3%, or about 3,900 votes out of 2.93 million cast. Obama lost here again in 2012, this time by 9.5%. An even bigger margin was achieved by Donald Trump in 2016, he won by nearly 19% over Hillary Clinton.

As 2016 marked the fifth straight Republican win, it is becoming a fairly reliable state for the GOP in presidential elections. Like many Midwestern states, population growth has been slower in recent decades than the country as a whole, resulting in declining electoral influence. From a peak of 18 electoral votes just prior to the Great Depression, Missouri has been reduced to 10 today.