Gravis Marketing, a nonpartisan research firm, conducted a random survey of 939 registered voters in Iowa regarding the presidential election and other areas of interest. The sample includes 356 Republican Caucus participants, 273 Democratic Caucus participants, and the remainder not planning on participating in the caucus, but are planning to vote in the regular elections. The poll has a margin of error of ± 3% [5% for Republican Caucus/6% for Democratic Caucus]. The total may not round to 100% because of rounding. The polls were conducted using automated telephone calls (IVR technology) and weighted separately for each population in the...