As we close in on the Iowa caucuses, it’s becoming clearer that everything is going right for Mitt Romney. He may not win Iowa, but right now, it looks like he’ll emerge from Iowa looking strong — and if the polling holds up, he’ll be the overwhelming favorite to win the nomination.

The reason things are looking so good for Mitt right now is that Ron Paul and Newt Gingrich are remaining competitive — at the expense of the one candidate who could give Mitt a real run for the nomination: Rick Perry. As the only other candidate in the race with conventional credentials and mainstream conservative positions on public policy, if Perry were to become competitive with Romney, it wouldn’t just be inconvenient for him; Perry could actually win. Fortunately for Romney right now, Perry still appears to be mostly going nowhere, but all he would have to do is rally to third to return to almost full viability.

By contrast, if Newt remains viable, he would represent less of a threat to Romney than Perry would. He scares Republican politicians and GOP-aligned group leaders because he would be a wild card in the White House. Ron Paul doing well in Iowa isn’t a threat to Romney either: Many GOP-aligned groups oppose most of his positions on public policy. Indeed, in a two-person race against Paul, Romney could campaign on being tough against terrorists and drugs while preserving popular portions of the federal government, all of which would help position him for the general election.

Looked at in this way, so far the polling in Iowa shows almost a perfect finish for Romney. According to Nate Silver’s latest numbers, Romney and Paul are close for first, with Newt hanging on for third and Michele Bachmann actually besting Perry for fourth. Romney couldn’t ask for a better scenario. Now, Silver’s projections are based only on current polls, so the late effects of Perry’s spending could easily still shake things up. But as long as Perry remains dead in the water, Romney — whatever happens in Iowa — will continue cruising towards the nomination.

Update: Nate Silver link fixed.