A new Des Moines Register poll shows that three of the four Republican candidates would beat President Obama in Iowa if the general election were held today.

Rick Santorum is in a statistical dead heat with Obama—48 percent to Obama’s 44 percent. The picture is similar for Mitt Romney, who would get 46 percent to 44 percent for Obama. Obama would garner 51 percent to Newt Gingrich’s 37 percent in the Hawkeye State.

But Ron Paul would beat Obama with 49 percent to the President's 42 percent, making him the only Republican to beat the margin of error.

Why are we still talking about Iowa, after all the caucuses were held back in January? Because Iowa is considered a swing state in the general election, critical to Obama’s re-election.

Hmm...Ron Paul, eh?

The guy who wants to shrink back from international military activism and conduct a foreign policy based on negotiations and peaceful coexistence? The Republican candidate who's the least socially conservative? The Ron Paul who wants to cut government spending more than anyone else? The candidate who wants to get rid of the Federal Reserve and return to the gold standard?

What does the level of support for Paul say about Iowa voters?

Well, it says that Independents as well as Democrats (included in this poll) in Iowa at this point favor the GOP "back runner" as opposed to the "front runner," whoever that is. (This week it’s Rick Santorum.)

The poll also underscores the great volatility of voters this year, not just in the GOP primaries, but also among the larger electorate: American voters are struggling with President Obama's policies, the still-fragile economy, the ominous and frightening national health care law, which nobody understands and which may be unconstitutional to boot. Obama also faces foreign policy challenges that are daunting. Think Iran, North Korea, the collapse of the Arab dictatorships—Libya falling apart, Egypt still in crisis, Syria descending into a civil war, a drug- and violence-infested Mexico.

Of course this is far too early to say anything definitive about the November general elections.

But there are some numbers we can drill out of polls that have a predictive value. According to the Register, “The president’s job approval is 46 percent in Iowa, just one point above his lowest low of 45 percent in September 2010. No president has been re-elected with a national approval rating under 49 percent, according to Gallup polling dating to 1964. It’s a watershed mark, and about 8½ months from the election, Gallup national polling Saturday had Obama at 46 percent—underwater.”

The poll also raises another highly negative condition for Newt Gingrich: he comes in not just last, but also a long way from beating Obama. It cannot be helpful to Gingrich’s campaign and fundraising to be so thoroughly buried.

I was also interested that at a rally in Kansas this week, Ron Paul said, “We’ve slipped away from a true Republic. Now we’re slipping into a fascist system where it’s a combination of government and big business and authoritarian rule and the suppression of the individual rights of each and every American citizen.”

Wow. A Republican said this? Maybe that's Paul’s appeal. He's a revolutionary, not a Republican.

I wonder if Paul’s supporters can vote for Santorum in November if he gets the nomination. And, of course, I still wonder if voters across the U.S. will actually feel comfortable with Ron Paul’s unorthodox positions, or if in the end they will prefer incrementalism.