According to the Votemaster, the recent decision by the Iowa Supreme Court striking down a state law which defines marriage as the legal union between one man and one woman, "immensely complicates" the 2012 race for the GOP...
For social conservatives like Gov. Sarah Palin (R-AK) and former Arkansas governor Mike Huckabee (R) it is a twofer: they can campaign for the Iowa caucuses by railing against (1) gay marriage and (2) activist judges. Iowa's Republicans are deeply conservative and by moving the hot-button social issues to the front burner, Palin and Huckabee benefit from this. Mitt Romney is currently against gay marriage, but Iowa Republicans can never be sure what position he will take a week later in New Hampshire.
If Palin and Huckabee finish first and second in Iowa, in whichever order, whoever finishes fourth will have a hard time recovering in New Hampshire. If the #3 finisher is a relative moderate, such as Romney or Gov. John Huntsman (R-UT), he could still have a good shot at winning the New Hampshire primary. While winning Iowa is no guarantee of getting the nomination (just ask Mike Huckabee), it certainly is a good start. As a consequence, the likelihood of the Republicans nominating a highly conservative, deeply religious candidate has been greatly increased by the Iowa court decision.
While it's still a bit early to be counting votes (straw or otherwise) in Iowa, the action by that state's Supremes should indeed make the race more interesting. Look for Mitt Romney to be talking up his opposition to gay marriage in the coming months.
Update: Politico shows it's ass (the long-eared variety) on the subject. Hee-Haw!