The two key ingredients to winning a primary are voter enthusiasm and a get-out-the-vote operation.  In a caucus, the organization is even more important.  You have to identify people in advance who will agree to go to caucuses, which is much, much more involved and time-consuming than simply voting.  It can be a process that goes on for some time, and only committed caucus-goers will go in for that.  That's why to be serious, you need an organization in every district and committed people you know by name who are going to show up.

Ted Cruz has that in Iowa.  Donald Trump does not.

Mr. Trump's Iowa director predicted that he would recruit a leader for each of the state's 1,681 Republican precincts by Thanksgiving. Instead, the first major training session for precinct leaders, heavily promoted in emails and conference calls, drew only about 80 people to West Des Moines last weekend, with about 50 participating online.

For its training session last weekend, the Trump campaign had sought out people who had attended rallies to be caucus leaders. The modest participation for the session in person and online contradicted Mr. Laudner's promise to have nearly 1,700 caucus leaders in place byThanksgiving, as he told NBC News in October.

Some of Mr. Trump's Republican rivals have spent months calling and knocking on doors to identify potential supporters to draw them out to caucuses, but Mr. Trump does not appear to have invested in this crucial "voter ID" strategy until recently.

The Trump campaign hopes to attract a surge of independents and disaffected Democrats on caucus night, but the latest data from the Iowa secretary of state show no significant growth in Republican registrations.

Of eight people interviewed at a Trump rally in Waterloo in early October, all gave the Trump campaign their emails. Contacted recently by a reporter, four of the eight said they had not received any follow-up. The others received a mass email asking them to volunteer for Mr. Trump, but they were uninterested[.]

Cruz and Trump are neck and neck in the polls in Iowa, but because Cruz has the much more developed organization, I think he is much more likely to win.

However, I do not believe that a victory in Iowa will translate into a victory in New Hampshire.  The political terrain there is simply too hostile to Cruz.  The most important battle, I think, will be fought in South Carolina, shortly after New Hampshire, where Trump has been holding a big lead...until today.

Trump, formerly with poll numbers in the 30s, is down to the 20s in South Carolina.  And Ted Cruz, who was formerly in the low teens, has just jumped up to 21% in the latest poll, only seven points behind Trump.  It is not hard to imagine that a Ted Cruz victory in Iowa could snowball into a victory in South Carolina.

If Ted Cruz wins South Carolina, he is on his way to winning the nomination.  Keep in mind that if Trump does not get an outright majority of the delegates (the magic 32% of the vote I keep talking about), he is unlikely to be the nominee, even if he has the most delegates.  Imagine if Trump has, say 45% of the delegates, and Cruz has 35% and Marco Rubio has 20%.  Trump could offer Cruz the vice presidency for his support, but a much more likely scenario is that Cruz would offer Rubio the vice presidency for Rubio's support.

There are possibly some tough times ahead for Donald Trump.  If he loses Iowa, it's trouble, and if he loses South Carolina, it's big, big trouble.

This article was written by Ed Straker, senior writer of NewsMachete.com, the conservative news site.