The first presidential nominating contest of the 2024 presidential election is set to start amid a deep Iowa freeze Monday — and for many Americans, how the system works is a mystery. Registered Republicans in the state will make their way through the snow and ice Monday evening to gather in schools and community centers and kickstart the long process of choosing their party’s nominee. Caucuses will take place in 1,657 precincts across the state starting at 7 p.m. local time. Firstly, they will choose a precinct chair and secretary. That chair will then invite candidates’ supporters to speak t…