Photo: Charlie Neibergall-Pool/Getty Images

One question posed by the bizarre rise of Newt Gingrich is whether or not he will implode in the Spinal Tap drummer pattern experienced by every other candidate who has challenged Mitt Romney. A second question is whether, failing that, the Republican Party can actually stop him. A third question is whether the Party actually wants to stop him. Let’s consider them in order.

Gingrich is notoriously erratic. But we are only six weeks away from the Iowa caucuses. It is possible that Gingrich manages to hold it together between now and then. And should he win Iowa, he may challenge Romney in New Hampshire (possibly with some help from Jon Huntsman), or at the very least gain enough momentum to overcome him in South Carolina and beyond.

Even assuming away any future meltdown, Gingrich is laden with personal and ideological baggage. Yet he seems to have perfected a smart strategy for deflecting any hostile attention: Attack the media. Gingrich’s incessant and often unprovoked media-bashing is one of the keys to his success. It converts every question about him into a tribal contest between conservatives and the hated Other.

The possible flaw in this strategy would be if right-wing media decide to go after Gingrich. Newt would be in trouble if Fox News started to harp on his marital history or past support for cap and trade. That could happen if Roger Ailes and various party poobahs emerge from their mountaintop castle and decide to anoint Mitt Romney as the nominee.

That would be the obviously sane course of action. Both observable evidence and common sense suggest that Romney would make a far stronger candidate. But Republicans have been disregarding political common sense with increasing frequency. Having the whole House vote for a budget that cuts taxes for the rich and privatizes Medicare yet stands no immediate chance of passage is not a smart idea. Nominating Sharron Angle and Christine O’Donnell is not a smart idea. There is less and less of a sense that those mountaintop castle meetings are actually working the way they’re supposed to.

At one level, it seems completely insane to not nominate Romney. Yet there is a logic to it. The worst thing that can happen to you as a party is for your president to compromise away your agenda, and party unity is far easier to organize in the opposition. The Republicans can block any plan to put a price on carbon emissions by President Obama. All the purists and all the party loyalists will vote as a block to stop it.

But suppose President Romney decides he wants to tackle cap and trade? He’ll split the party between purists, who will vote against Romney’s climate plan, and loyalists, who would be happy to vote for a Romney-endorsed plan, which they would oppose if put forward by Obama. And then support for cap and trade will be marginalized as a position, just as opposing any Medicare drug benefit was marginalized after George W. Bush supported it. In the long run, keeping your party together is more important than winning. You can always come back from a loss, but you can’t come back from apostasy. Another way to put that is, as a liberal, I’d much rather have a Republican president dedicated to a flat tax than a Democratic president dedicated to a flat tax.

Now, the tricky thing with Gingrich is that he is not exactly a perfect vehicle for right-wing purity. But if you view Gingrich’s positions as a graph, with erratic spikes to the left (support cap and trade!) and to the right (fight the secular socialist machine!), the general thrust is still one of maximal partisan conflict. If I’m a Republican, I worry a lot less about Gingrich selling me out than Romney selling me out.