Yes, Kansas Senator Sam Brownback visits the Field of Dreams today, so we can't beat the very overused phrase to death: Is this heaven? No, it's Iowa. (What would journalists do if the book and movie had been set in Nebraska?)

RCP has landed in Des Moines, in advance of tomorrow's Republican straw poll 30 miles north in Ames. Today, we will offer almost live updates from the Des Moines Register's Soapbox series, where ex-Massachusetts Governor Mitt Romney and ex-Wisconsin chief exec Tommy Thompson make remarks this afternoon.

Both candidates have much at stake tomorrow: Can Romney pull off a win big enough to be seen as, well, a win? And can Thompson convince enough Iowans to mark down his name to remain in the race?

We'll also report from the AARP forum, where former Arkansas Gov. Mike Huckabee addresses the state fair crowd, and a GOTV rally with Kansas Senator Sam Brownback. The two have been battling over social conservatives, and for one of the two, tomorrow's straw poll may signal the end of the line. But, as our informal poll of GOP leaders in Iowa suggests, will they have to contend with a strong push from Colorado Congressman Tom Tancredo?

Meanwhile, we're thoroughly flummoxed by Texas Representative Ron Paul. He's running ads urging people to head to Ames tomorrow (sandwiched between Green Day and Steppenwolf on local radio) though his campaign says they aren't conducting the same get-out-the-vote effort as others. Ames is not a must-win for Paul, who has the cash to continue and has a following on the internet (but does his campaign know it?). But every vote for him is a vote not going to Thompson, Romney, Huckabee and Brownback.

Finally today, Politico's Roger Simon reports that Iowa Gov. Chet Culver will do anything in his power to keep the caucuses in 2008, instead of moving them to this year. The new governor, his Secretary of State and the chairman of the Iowa Democratic Party hold a press conference at 2:45 Central Time, at IDP headquarters, to discuss the situation. Stay tuned for any developments there.

Keep checking this space for news as it happens from the Hawkeye State.