(Andrew Harrer/Bloomberg) (Andrew Harrer/Bloomberg)

On last night’s edition of “The Last Word” on MSNBC, host Lawrence O’Donnell made like Maureen Dowd, unspooling an extensive psychological breakdown of the twisted relationship between Fox News’s Bill O’Reilly and Rush Limbaugh. Their mutual antipathy, argued O’Donnell, is so strong that they can’t bear to acknowledge each other on their respective airs.

Yet Limbaugh yesterday couldn’t resist, citing O’Reilly’s news-making condemnation of the case against gay marriage on his Tuesday night show. “The other side hasn’t been able to do anything but thump the Bible,” said O’Reilly in a chat with Fox’s Megyn Kelly.

The biblical reference was enough to smoke out Limbaugh, who cited the remark on his radio show yesterday. “Well, so how many of you who watch Fox are Bible-thumpers? Do you think there are any Bible-thumpers who watch Fox? Because last night, you were sort of marginalized on ‘The Factor’ as not having a compelling argument and just being a bunch of Bible-thumpers,” said Limbaugh.

O’Donnell finished his riff by noting that O’Reilly has had an evolution on gay marriage. In 2009, for example, the popular host said that if same-sex marriage had been permitted in California, “then anybody could have gotten married. You could have married a duck.

Despite his own very clear shift on the issue, O’Reilly on Tuesday night nailed Bill Clinton and President Obama for their politically motivated respective evolutions on gay marriage. It was a fine point and one made on Wednesday morning by Matt Gertz of Media Matters.

But why does O’Donnell burn six minutes of precious MSNBC air time on O’Reilly (and Limbaugh)? Doesn’t that just enhance the stature of a cable-news competitor? The Erik Wemple Blog posed the Fox-obsession question to MSNBC President Phil Griffin in mid-March, following the news of Ed Schultz’s move to a weekend slot. Griffin’s response:

I don’t want to be overly focused on Fox, but sometimes our folks will set the record straight, and if it’s right, I don’t have a problem with that. If you look at our network, you’ll see that we’re not here to spend a lot of time talking about Fox…. I don’t think we should be obsessed about Fox, because we’re not.

Schultz’s program, Griffin said, had addressed Fox’s coverage “from time to time, and that was all right. It’s not an obsession.”

Whenever MSNBC considers highlighting the latest O’Reilly outrage, it may want to take a look at the dust jacket of the O’Reilly book “Killing Lincoln“: “He is, perhaps, the most talked about political commentator in America.”

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