MS NOW

Caucus math: An NBC News primer

The process doesn't work the same way as the typical Election Day ritual — and Republicans and Democrats approach the caucuses differently.

Supporters of Sen. Bernie Sanders at a rally for campaign workers in Ottumwa, Iowa, Jan, 28, 2016. (Photo by Mark Peterson/Redux for MSNBC)
Supporters of Sen. Bernie Sanders at a rally for campaign workers in Ottumwa, Iowa, Jan, 28, 2016. 

Carrie Dann

Mark Murray