Figuring out how the Iowa Caucus system works has never been easy, but with new rules in place this year to help Iowans outside the state participate in these first-in-the-nation Caucuses, it's more complicated than ever. Anthony Salvanto works with CBS News Reporter Adam Brewster (@adam_brew) to demystify the process and explain why 15% is the number to get. Learn more about your ad choices. Visit megaphone.fm/adchoices