As I said, "A lot of theories are going to be tested, and a lot of hopes are riding on the outcomes."
Here's Dan Balz, at the Washington Post, "The big Iowa test: Can Trump and Sanders turn enthusiasm into votes?":
DES MOINES — With campaign events all across Iowa on Saturday overflowing with voters, the Republican and Democratic contests have been reduced to the same question: Can the muscle of traditional and methodical organizing overcome the energy and enthusiasm of a pair of unconventional candidates in this unconventional race?More.
After a year in which voter anger and dissatisfaction with Washington have propelled insurgent candidates and shaped the political terrain, Iowa voters will offer the first clues as to whether what has taken place up to now was an aberration or a new normal in American politics that will continue to course through the election battles until November.
In the Democratic race, Hillary Clinton is seeking to fend off an unexpectedly strong challenge from Sen. Bernie Sanders (Vt.). Among Republicans, the principal battle pits Donald Trump, who has broken almost every rule of how to run an Iowa campaign, against Sen. Ted Cruz (Tex.), whose campaign is a textbook example of what is known here as “the Iowa way.”
The latest Des Moines Register-Bloomberg Politics poll, released Saturday night, showed Trump leading the Republican race at 28 percent, followed by Cruz at 23 percent, Sen. Marco Rubio (Fla.) at 15 percent and Ben Carson at 10 percent. Among Democrats, Clinton held a statistically insignificant lead over Sanders, 45 percent to 42 percent. The Iowa poll has had an excellent track record in past caucus cycles, particularly in its final measurement of the race.
The most important unknown in the final hours was how many Iowans will turn out for the caucuses Monday evening. The bigger the numbers, the better for Trump and Sanders, according to projections by several campaigns.
Iowa Republican Party Chairman Jeff Kaufmann said he “can’t envision” his party not beating its previous turnout record of about 122,000, set four years ago. He said telephones at party headquarters have been ringing constantly for the past week, day and night, with people wanting to know how and where to caucus. “It is just nonstop here,” he said. “We’ve got literally hundreds of calls a day. . . . I’ve got a hunch a lot of these folks are going to show up.”
Trump returned to Iowa in grand fashion, roaring his private jet low over a huge crowd in Dubuque before rolling to a stop at a hangar. He implored the crowd to go to the caucuses. “I don’t care what it is,” he said. “If you don’t get out, we’re wasting time. . . . We have a chance to do something so historic.”
PREVIOUSLY: "Turnout Is Name of the Game in Monday's Iowa Caucuses."