“In the election for U.S. Senate, Republican incumbent Joni Ernst (47%) and Democratic challenger Theresa Greenfield (47%) are locked in a tight battle. Ernst had a slight 48% to 45% edge among registered voters last month. Libertarian Rick Stewart earns 1% and another 4% are undecided. The race remains close, but with a nominal lead for the Democrat, when looking at likely voters under either a high turnout (49% Greenfield and 46% Ernst) or low turnout (48% Greenfield and 47% Ernst) scenario” – Monmouth University.