Today I asked a senior Democratic campaign operative what variables he's watching in the Iowa home stretch. He said the key one is the final Des Moines Register poll; his understanding is that there's one more to come. That will be a big event--especially if one candidate shows momentum that makes him or her look like a winner going into caucus day. (Voters often follow witnessed momentum.) It's especially significant given that the DMR's poll is held in high esteem within the business.

Obviously everyone wants to be the frontrunner. But the poll could also reward a late surger: The last DMR poll in 2004 showed John Kerry in the lead, but the paper played up a late John Edwards surge which may have enhanced Edwards's caucus-night surprise. ("The 'Edwards Surges' subhead was every bit as important as the 'Kerry Leads' headline," says the operative.)

It's not clear when the poll might appear. This person, who has extensive Iowa experience, says final DMR polls usually appear on the Sunday before the caucuses. But a poll published this weekend would probably mean polling conducted immediately after Christmas, with the uncertain effect of large numbers of voters in transit. Alternately, the poll might be published the day before the caucuses (as it was in '04, when they were held on a Monday). But that could require polling around New Year's, which might also have funky effects.

Anyway, brace yourselves. 

P.S. I dug up the final 2004 poll, which turned out to be quite predictive. Here's the top to their story:

Kerry, Edwards surge;
Iowa Poll shows many voters still open to change; 8 points separate top four candidates

Jonathan Roos, Staff

A late surge by Democratic presidential candidates John Kerry and John Edwards has pushed them slightly ahead of long-standing front-runners Howard Dean and Dick Gephardt in the race to win Monday's Iowa caucuses, a new Des Moines Register poll shows.

Kerry, a U.S. senator from Massachusetts, leads the Iowa Poll with 26 percent of likely caucus participants naming him their first choice for the presidency. The poll, conducted Tuesday through Friday, also showed him gaining strength as the week wore on.

Edwards, a North Carolina senator who was in single digits in an Iowa Poll taken two months ago, follows in second place at 23 percent -his highest finish in any media poll of Iowans.

Dean, the candidate who seemed to be in the driver's seat as recently as two weeks ago with a key endorsement from Iowa Sen. Tom Harkin, has slipped to third at 20 percent. But the former Vermont governor remains within striking distance of the lead in an unusually close race in which almost half of caucus-goers say they could still change their minds.

Dick Gephardt, the Missouri congressman who is counting on a strong finish with help from labor unions, has dropped to fourth place at 18 percent. Gephardt won the caucuses in 1988 before losing the nomination to Michael Dukakis.

"The character of the race has changed dramatically. Kerry has surged into the lead, followed by an even more spectacular move by Edwards into second place," said J. Ann Selzer, the Register's pollster.

"The luster has faded from Dean's campaign, and Gephardt has stumbled down the stretch as well," Selzer said

Michael Crowley