Missouri voters chose 10 electors to represent them in the Electoral College via a popular vote pitting incumbent Democratic President Barack Obama and his running mate, Vice President Joe Biden, against Republican challenger and former Massachusetts Governor Mitt Romney and his running mate, Congressman Paul Ryan.

Consequently, the state was not heavily contested by either side in 2012, and Romney ultimately carried Missouri by the largest margin since Ronald Reagan's 1984 landslide.

In September 2008, the Republican National Committee adopted a set of rules which included a provision that no states except Iowa, New Hampshire, South Carolina, and Nevada were allowed to begin the process of delegate selection (including binding primary elections) before the first Tuesday in March of an election year.

In a compromise solution, it was decided that Republican primary election would be made non-binding and instead delegates would be nominated by separate caucuses in late March, a move estimated to cost the state US$7,000,000.

[8] The primary was not to affect the selection of Missouri's delegates to the 2012 Republican National Convention, so it had no official effect on the nomination and was widely described beforehand as a "beauty contest".

However it was seen as an opportunity for Rick Santorum to face off against Mitt Romney due to the absence of Newt Gingrich, who missed the filing deadline[9] and was not on the ballot.

Because there is no vote on candidate preference, neither the Missouri GOP nor any election authority will have or release any data regarding the 'winner' of the caucuses.

Santorum was to appear personally at some caucuses, which The New York Times described as "part of the campaign's county-by-county strategy to try to outflank Mr. Romney and catch him in the delegate race".

Obama is the only president of either party since William McKinley to win two terms in the White House without carrying Missouri either time.