One of the pillars of the Iowa Republican Party has been white evangelicals. According to this article in the Cleveland Plain Dealer they are feeling like they don't have a candidate in the 2008 presidential race. They find Giuliani too socially liberal, they don't trust McCain, Romney is a Mormon, Brownback and Huckabee are long-shots. If this was to hold up until the GOP nomination, it could lead to religious conservatives sitting out the 2008 election. That would have huge consequences for Republicans up and down the ballot.
People get in trouble in politics when they start believing their own bs. Since 2004 white evangelicals in the Republican Party have bragged about their power over their party. That has led to those voters who don't share their beliefs getting worried and becoming more active themselves. In the Ohio 2006 election the Republican Party learned that a candidate who just appeals to part of a political party's base gets beat. If you don't believe us, just look at the totals in the Strickland-Blackwell campaign for governor.
It will be interesting to see what the reaction of the religious right is to the fact that Romney is now leading in the "money" primary and Giuliani is leading in the polls. Will they redouble their efforts to try and come up with a person they see as more acceptable? Will they suck it up and back one of the three front-runners? Or will they take their marbles and go home? The 2008 election chances for the GOP may depend on their choice.