Just looking at the co-hosts of the event in Iowa yesterday for the Republican presidential field offered a hint of what was to come.

The “Thanksgiving Family Forum” was organized and sponsored by three groups: the James Dobson-founded Focus on the Family, a religious right powerhouse known for its bizarre cultural agenda; the National Organization for Marriage, perhaps best known for its unintentionally hilarious anti-gay commercials; and The FAMiLY Leader, an Iowa-based group of extremists that put together “The Marriage Vow” for GOP candidates, which argued, among other things, that slavery wasn’t that bad for African-American families.

Despite — or more likely, because of — the radicals behind the forum, six GOP presidential hopefuls showed up to pander to the religious right voters, each vowing to be more pious than their rivals. The only two candidates who weren’t there were Mitt Romney, who declined an invitation, and Jon Huntsman, who wasn’t invited at all.

The result was an event that was tough to watch.

Looking to court this state’s critical voting bloc of evangelical Christians, Republican presidential candidates sharply attacked secularism and the Supreme Court while calling for greater restrictions on abortion and gay rights at an event here on Saturday. At a forum on moral values, which was held at First Federated, an evangelical church in Des Moines, the six candidates in attendance largely stuck to Republican orthodoxy and avoided criticizing one another. Instead, they called for dramatic changes in current law to achieve conservative aims. To limit abortion, former House speaker Newt Gingrich, one of the leading candidates in polls here, proposed a federal law defining “personhood” as starting at conception, similar to a provision backed by abortion opponents that was rejected earlier this month by voters in Mississippi. Texas Gov. Rick Perry said he supported provisions that would limit the ability of gay couples to adopt children, while businessman Herman Cain called for changing provisions in the tax code that restrict churches’ involvement in politics if they want to keep their tax-exempt status. Several committed to supporting state same-sex marriage bans and eventually a constitutional amendment to prohibit it, although libertarian candidate Rep. Ron Paul (Tex.) said the issue should be dealt with by churches and families instead of the government.

Paul may have been the only candidate on the stage to oppose an anti-gay constitutional amendment, but he was quick to express his unyielding support for the Defense of Marriage Act, which President Obama and congressional Democrats are eager to repeal.

So, what did we learn from the event? That for all the focus on economic and fiscal issues at the national level, much of the Republican base is still preoccupied with a culture war — and most of the Republican presidential candidates are only too pleased to tell these voters what they want to hear.