Sweet column: In Iowa, 2nd choice deals and alliances may determine Democratric winner.

DES MOINES, Iowa — After almost a year of manic focus on Democrats John Edwards, Barack Obama and Hillary Rodham Clinton, the Iowa caucus outcome Thursday may depend on the front-runners’ allies cutting deals with the backers of Joe Biden, Chris Dodd, Bill Richardson and Dennis Kucinich.

That’s because in many precincts, it will take two rounds of voting to determine how many delegates each contender will earn.

The front-runners, in the closing days of the campaign, are pleading not only to be the first pick of voters — but also to be the second choice if a person’s favorite is knocked out in the first round.

Obama on the stump has been quite explicit lately: ”If you’re already committed to someone else, please make me your second choice.”

Biden may be the main beneficiary of this convoluted two-bites-at-the-apple system, where personal and political relationships of the people at a neighborhood caucus come into play, as well as the skill of a precinct captain working back channels.

Another factor is this: Die-hard Clinton, Obama and Edwards backers would rather back second-tier contenders in second-round voting than each other.

“We know we will have three candidates who will not help each other,” said Biden spokesman Larry Rasky on Monday, referring to the front-runners. ” . . . They are competing for first.”

Biden may even come in fourth — which for him would be a tremendous victory and be his ticket to admission to the New Hampshire Democratic debate on Saturday, limited to leading contenders.

“There is a lot of fluidity in this race right now,” said David Plouffe, Obama’s campaign manager, on Monday morning.

“A lot of undecideds, a lot of people looking for a second-choice candidate,” Plouffe said.

Since electability looms as a big factor in both voting rounds, Plouffe and the campaigns of Edwards, Biden and Richardson all issued memos about their general election potential on Monday.

A quick primer on the Iowa Democratic caucus (the Republicans just have a straight vote):

There is no secret ballot box in a caucus, no absentee voting. Everything is done out in the open, so people will know who is for whom.

There are 1,781 precinct caucuses called to order at 6:30 p.m. Thursday. While there will be some exceptions in the smaller precincts, a “viability threshold” will have to first be determined by people physically moving around to stand in sections of a room for their candidate.

If a candidate fails to meet a threshold — in most cases 15 percent — they are considered non-viable

After 30 minutes or so of wheeling and dealing, there is a re-alignment with several strategic options. Using Biden as an example, it could unfold this way:

Biden is found non-viable in a precinct and supporters re-align to help a front-runner

A front-runner, in return, in another precinct, would send surplus backers over to Biden to make him viable and eligible to pick up a delegate. Better Biden than someone else.

Non-viables can join with non-viables. Biden and Dodd backers, for example, could make a deal to help each other.

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