Another week, another fashionable anti-Romney candidate for Republicans to focus on. Even while last week’s mini-boom for Newt Gingrich is still drawing headlines, a new Bloomberg poll gives heart to perennial candidate Ron Paul.

Paul leads Romney in Iowa, the first state to vote, by two points, 19% to 17%, in what is almost a four-way dead heat: Gingrich is on 18%, while Herman Cain still narrowly holds the lead at 20%. Among those who say they’ve made up their minds, however, Paul is well clear with 32%.

This isn’t particularly surprising; back in August, Paul came second in the Iowa straw poll, only 0.9% behind Michele Bachmann, whose chances have since been written off.

But this is a good time to talk about Paul, since American military adventurism is in the news again, with the plan to station US marines in Darwin as a counterweight to Chinese power. Paul is easily the most anti-military of the Republicans: he would bring all of America’s troops home, withdraw from NATO and the United Nations, and slash defence spending (as well as pretty much every other sort of spending).

That’s not the only thing that puts him outside the Republican mainstream. He’s also opposed to drug prohibition and, as he made clear in the most recent televised debate, he’s against torture: which, shockingly, was very much the minority position. Cain, Bachmann and Rick Perry were all enthusiastic about dragging their country back to the 16th century, while even Romney avoided any condemnation of torture.

Barack Obama promptly moved to take advantage with a statement against waterboarding: “That’s not who we are. That’s not how we operate.” That statement, however, would seem to put him in breach of America’s mandatory obligations under the Convention against Torture to investigate and punish instances of torture; the lack of any moves to do so suggests that even Obama is not sure how far public opinion is on his side.

Among the Republican base, there’s not much doubt that Paul’s views are unpopular. Although he fits the Tea Party template in other ways — he is virulently anti-choice, and exudes the standard disrespect for blacks, Mexicans and the poor — it is generally assumed that defence and national security have become so central to the Republican position that a dissenter on them has no real chance at the nomination.

The next couple of months will test whether that conventional wisdom is correct. There’s no doubt that Paul has a passionately loyal following (the internet is his particular strength), and among this field his extremism and general crankiness are not enough to rule him out. And since almost everyone else has had their moment in the sun it’s only fair for Paul to have his turn, until and unless voters take fright at his scepticism about the military.

For what it’s worth, I think they will. Although there have been occasional Republican grumblings against the war in Afghanistan and rather more against the intervention in Libya, the party has a huge emotional investment in the national security state, as evidenced by its continued refusal to countenance cuts in military spending.

It seems that the Republican Party has a capacity to distinguish between different sorts of military intervention. Wars that showcase American power, like Iraq and Afghanistan, are praiseworthy; “nation-building” exercises, which might actually help people (Bosnia, Somalia, Libya), meet with disapproval. Paul, who opposes both, just looks like the candidate who didn’t get the memo.

No doubt Ron Paul has many faults, but this time it’s his virtues that will sink him.