A brief history of the Hawkeye State’s caucus, and some areas to watch.KEY POINTS FROM THIS ARTICLE— Monday night’s Iowa Republican caucus kicks off the presidential nominating season.— The caucus has a spotty history of voting for the eventual nominee, particularly on the Republican side, although Donald Trump is a big favorite both in Iowa and nationally. Ron DeSantis is under the most pressure to perform, as he has basically bet his entire campaign on Iowa.— To the extent frontrunning Donald Trump shows weakness, look for it in places like the Des Moines suburbs as well as a couple of counties with major universities.— Meanwhile, a quartet of counties in the state’s northwestern corner should give us some indicators of where the Republicans’ strongest religious conservatives are in this race.