5:17 p.m.: On MSNBC, Keith Olbermann reported that “entrance polls” show stronger support for Clinton and Obama than other Democratic candidates, while there is stronger support for Romney and Huckabee among GOP voters. Olbermann cautioned that these numbers are very soft because of the dynamics of caucusing.

Another indicator from MSNBC: Many Democratic caucus sites are filled above capacity. It’s purely anecdotal but at a site where only 86 people caucused in 2004, well over 200 people have shown up tonight.

5:40 p.m.: First numbers released put Edwards and Huckabee in the lead.

5:54 p.m.: Latest Dems: Edwards 34 percent, Clinton 33 percent, Obama 33 percent.

5:58 p.m.: Latest GOP: Thompson in third — Huckabee 36 percent, Romney 23 percent, Thompson 14 percent.

6:00 p.m.: MSNBC calls GOP vote for Huckabee.

6:10 p.m.: MSNBC: 60 percent of GOP voters tonight self-identified as born-again or evangelical.

6:15 p.m.: With 56 percent in, delegate counts: Obama 35 percent, Edwards 33 percent and Clinton 31 percent, via MSNBC. Chris Matthews insists this is a “huge” defeat for Clinton.

6:26 p.m.: MSNBC calls the Democratic caucus vote for Obama — Edwards second, Clinton third.

6:43 p.m.: MSNBC: Obama 37 percent, Edwards 30 percent, Clinton 30 percent. Tom Brokaw is on. Olbermann: Pat Robertson won Iowa in 1988.