As I reported earlier today, Herman Cain’s gibberish on abortion could cost him badly in Iowa and with Christian conservatives more generally. He’s been high in the polls in large part because he has, or had, presented himself as an evangelical. His latest comments are already reverberating in Iowa and beyond.

A GOP operative in Iowa told me bluntly, “This unforced error is detrimental. This misstatement will be the marker referenced as to when Herman Cain blew his shot at the presidency.” Social conservatives take this issue very seriously.

Meanwhile, Penny Nance, the head of the 500,000-strong Concerned Women for America e-mailed me: “Last week Herman Cain said he didn’t support a federal marriage amendment, this week he has backed away from his earlier position on the sanctity of human life. Herman Cain needs to decide whether or not he is a social conservative. The issue of life is like the issue of slavery, it is an inalienable right. The life issue is a dividing line proving whether or not a leader’s moral compass is intact. This is not a point on which social conservative women will negotiate. Cain needs to figure out what he believes.” Of the marriage amendment, Nance was referring to Cain’s comments on gay marriage on Meet the Press .

Cain has managed to offend or worry each of the three main issue-blocs within the GOP. His 9-9-9 plan has been panned by fiscal conservatives. His remarks and then backpedaling on trading Gitmo detainees for a single American hostage alarmed hawks. And now on marriage and abortion, he’s put off the social conservatives. If he can’t satisfy any group that he knows what he is talking about on their key issues, it’s hard to see how he can remain at the top of the heap.

Cain has another problem: He’s been absent from Iowa, a must-win state. Without an established relationship with caucus-goers and a network of supporters, he’ll be hard-pressed to smooth over the rough edges on his policy blunders. As voters begin to pay more and more attention, what they are hearing is largely negative news about Cain. Negative news is a problem for any presidential candidate, especially one without a professional staff experienced in presidential politics.