Bill Brown has practiced law for 30 years, and currently serves as the Chair of the Board of Directors of the Iowa Association of Business and Industry, Iowa's largest business trade association. In the Iowa Des Moines Register, he explains the unlikely origins of legalizing SSM in Iowa:

For many, it is difficult to understand how we got to the point that a court would require the state to recognize same-sex marriage. Recognition of same-sex marriage would have been unthinkable to Iowans who approved the Iowa Constitution in the 1850s. To understand how we got here, looking back into recent Iowa Supreme Court precedent is instructive.

In 1994, the Iowa Legislature passed a gambling tax system that imposed a higher tax rate on racetracks than on riverboat casinos... Naturally, the racetracks were nonplussed about paying a higher tax rate than their brethren who operated riverboats, and they went to court to declare the legislation invalid. The case found its way to the Iowa Supreme Court in 2002, and the court held the tax system to violate constitutional equal protection provisions...

The state then appealed the case to the U.S. Supreme Court, which held unanimously in its 2003 decision that Iowa's gambling tax system did not violate federal equal-protection provisions... Despite the [Supreme] court's prior statements that Iowa courts were to apply the same analysis in considering both the federal and state equal-protection claims, on remand the Iowa Supreme Court held that the tax provisions violated Iowa's equal-protection provisions.

Here's how proponents of SSM took advantage of this bad precedent set by the Iowa Supreme Court:

For proponents of same-sex marriage looking for a new legal venue in which to assert their claims, this was manna from heaven. If the Iowa courts would find a taxing statute such as this in violation of equal protection, surely they would be even more sympathetic to the gay rights lobby. This presented an ideal opportunity to spread their influence in middle America.

Gay rights proponents led by Lambda Legal then recruited Iowa plaintiffs to seek to invalidate Iowa's defense of marriage law, ultimately resulting in the 2009 decision invalidating Iowa's statutory restriction against same-sex marriage.

Next, Brown explains why this background has bearing on the Iowa retention vote - which essentially fired three of the judges who legalized SSM in Iowa:

Those who assert that the judicial retention vote which removed three Iowa Supreme Court justices from the bench was all about one case need to consider this background. Effectively the Iowa Supreme Court invited Lambda Legal to challenge Iowa's marriage laws with its gambling tax decisions earlier in the decade.

While the Iowa same-sex marriage case clearly provided the broad based emotional appeal to remove the three justices last year, the outrage expressed by the electorate is not limited to one case. Iowans simply don't like unelected and largely unaccountable judges overriding policy decisions made by their democratically elected citizen Legislature.