I wish to address a comment left on this blog, which said, in effect, "California overturned their gay marriage. What makes Iowa different?" Great question!
Before I start, I should mention there is a distinct possibility that gay marriage could be overturned in Iowa. As pointed out, Iowa is seen as more conservative than California. And conservatives tend to vote against gay marriage to a greater degree than do liberals.
But there are differences which give me hope for Iowa. After spending a long time pondering the question, I think some reasons for the difference:
1) Iowa has only marginally more conservatives. A look at California voting pattern shows that in 2008, the Obama-McCain split was 61-37 (a 24-pt spread) and in 2004, the Bush-Kerry split was 45-54 (9-pt spread). In Iowa, 2008 results were 54-45 (9-pt spread) and in 2004 were 50-49 (1-pt spread). 2008 was actually abnormal in being such a large difference between the two states, with 2004 being more the norm. Iowa has more conservatives, but in general where California is a 60-40 liberal-to-conservative state, Iowa is a 50-50 state.
2) Pro-gay groups in California were complacent. California was a test for pro-gay campaigners, one which they failed miserably. The Advocate did a post-mortem on the campaign for "No on Prop 8" and came to the conclusion that a large portion of the fault lay with those running the campaign in thinking that California would swing their direction. Iowa will be different. Nobody will assume Iowa will be an easy ride. But moreover, every pro-gay marriage group will have large incentive to cover up their past mistakes by putting in an over-the-top effort to help maintain same-sex marriage in Iowa.
3) Iowa's constitution is hard to change. California is singularly unique in how easy it is for citizens to change its state constitution; all that is required is a simple majority vote (50% plus 1 vote) and any addition or subtraction can be made from the constitution, provided it does not abrogate "core rights". Iowa is not the same, in that all changes require ballot measures that must be approved by two consecutive legislative sessions prior to being put before the voters. Whereas the California constitution has been amended/revised "500 times by referendum and about 40 times by initiatives since its adoption in 1879", the Iowa constitution has only been amended 36 times since 1857. This difference will make it much more difficult to change. The closer comparison for Iowa is Massachussets, which also requires consecutive sessions for a ballot initiative and has never gotten it passed, rather than California. Another state that comes to mind is Indiana, which is quite conservative, but still has not voted for a gay marriage ban because the legislature has still not passed the ballot intiative in two consecutive sessions.
4) Time is on the side of civil same-sex marriage. People don't like changing the status quo, and so over the short term, a decision to change toward same-sex marriage will not sit well with many people. But over a longer period of time, people will become acclimated to the new decision. Moreover, it becomes exceedingly difficult to call null-and-void the marriage of those couples who are already married (this is a key problem being considered by the courts now in California). In 3 or 4 years when voters are perhaps able to vote on this issue, they will see that the state hasn't fallen apart. They will see thousands of couples who have been married and would have to be divorced. And they will see additional states where marriage and/or civil unions are permitted. California will soon rule, perhaps reinstating marriage and, even if not there will be a 2010 ballot initiative which will potentially reverse it. Vermont and New Hampshire will vote for gay marriage. New Jersey, Maine, and New York may be shortly behind. The landscape will be quite different in 2013/14, which will help reinforce the maintenance of same-sex marriage in Iowa.
Now, let's just hope that the above reasons are enough and same-sex marriage stays!