DES MOINES, Iowa: The Iowa Democratic Party released partial results of its kickoff presidential caucus after a daylong delay late Tuesday showing former Midwestern Mayor Pete Buttigieg and progressive Vermont Sen. Bernie Sanders leading the opening contest of the party's 2020 primary season.

The results followed 24 hours of chaos as technical problems marred the complicated caucus process, forcing state officials to apologize and raising questions about Iowa's traditional place atop the presidential primary calendar.