The poll showed Huckabee with the support of 39 percent of likely GOP caucus-goers, compared to 17 percent for Romney. Fred Thompson was in third at 10 percent.
A few caveats: Accurately figuring out who will attend caucuses in Iowa is notoriously difficult. The Newsweek poll is also an outlier compared to other polls, all of which show Romney and Huckabee deadlocked. Finally, the poll has a relatively high margin of error: 7 percent. A PDF of the poll is available here.
Still, the numbers are so dramatic that there's no way they won't raise eyebrows. And if they're true, it may not spell doom for Romney, because he would go into caucus night with much lower expectations than before. "Don't be so quick to write Romney's obit," CBS News Chief Political Consultant Marc Ambinder tells us. "A poll like this is as much a gift to him as it is good news for Huckabee."
By the way, the poll also included the Democrats. The result there is more in line with what we've seen lately and shows Barack Obama slowly gaining momentum. Among likely caucus-goers, he led Hillary Clinton, 35 percent to 29 percent. That gap is equal to the survey's 6 percent margin of error, however.