November 22 was the deadline for presidential candidates to file in Missouri’s February 7 presidential primary. See here for the list of candidates. The Republican presidential primary is only a “beauty contest”, with no direct impact on which delegates are chosen. Republican delegates are chosen at March caucuses.
The Libertarian and Constitution Party presidential primaries are also non-binding. No one filed for the Constitution Party primary, and James Ogle is the only person who filed in the Libertarian primary. Ballot access required a fee of $1,000.
Only four names are on the Democratic presidential primary ballot: President Obama, Darcy Richardson, Terry Randall, and John Wolfe.
Newt Gingrich did not file, and his campaign has not responded to questions from major newspapers asking why he didn’t file.