Bring it on! No, really. (AP Photo/Andrew Harnik)
Opinion writer

The smart Beltway money has suddenly decided, based on a handful of polls, that we’ve got ourselves a real race on the Democratic side. A new Monmouth University poll finds Bernie Sanders leading Hillary Clinton in New Hampshire among likely Democratic primary voters by 53-39. Meanwhile, a new Quinnipiac poll finds Sanders leading Clinton in Iowa by 49-44 among likely Democratic caucus-goers. A new Public Policy Polling survey puts Clinton up in Iowa by 46-40, but that’s a tightening, and the polling averages clearly suggest a tightening in Iowa as well.

So Sanders may well be surging. We’ll know more tomorrow, when the Des Moines Register poll — the gold standard in Iowa polling — is set to drop.

But in the event that the Sanders surge continues, but doesn’t take down Clinton — and a Clinton loss by no means can be ruled out — it could prove a good thing for her candidacy.

Nate Silver is taking Sanders’ surge in Iowa seriously:

It’s probably worth being at least a little bit skeptical of a polling swing like this one without any major news events to precipitate it. But here’s the thing: You can make the case that Sanders was underachieving in Iowa before. As we’ve been saying since July, it’s entirely plausible that Sanders could win the state.

From a 30,000-foot level, the demographics of the Democratic caucuses here should look pretty similar to those of the New Hampshire primary. Meaning there will be lots of white liberals. And while Sanders doesn’t have the advantage in Iowa of hailing from a neighboring state, as he does in New Hampshire, he has some other things working for him here: lots of college students and caucuses that rely heavily on voter enthusiasm, which could make his ground game more important.

If Sanders doesn’t win Iowa, and Clinton pulls out a win, it will mostly offset a Sanders victory in New Hampshire, and then it’s on to the later contests, where more diverse electorates will probably give Clinton and her broader coalition a substantial advantage. So it’s all about Iowa.

But Sanders could win there. If he does, and if he goes on to win New Hampshire, it’s perfectly possible that it could shift the dynamic in other states. It’s a strange year. Predictions are perhaps even more perilous than usual.

But as Silver has also documented, it’s also perfectly possible that Sanders could win both early contests and go on to lose the nomination by losing pretty much everywhere else. That’s largely because Clinton performs very well among minority voters, and you would probably have to see a massive exodus of them from Clinton to Sanders for him to win the nomination. Make no mistake: A Sanders win in both early states would unleash gale force winds of pundit doom-saying for Clinton. But Dem voters in the later contests may not play along.

And if Clinton does go on to win later contests, and the nomination, a stiff Sanders challenge along the way could prove all to the good for her.

The structure of this primary so far has not been uniformly beneficial to Clinton. The Democratic National Committee set up too few debates, on a schedule that helped guarantee a smaller audience, that — intended or not — may have served to insulate Clinton from high profile challenges. This has not served Clinton well. She has been at her best when directly challenged in high stakes settings, such as during the debates we did have and during the marathon showdown with Benghazi committee Republicans in the fall. Exposure and challenge have been good for Clinton.

If Clinton had wrapped up the nomination with little challenge, it might have spared the Clinton campaign and top Democrats who support her some tense moments. But a serious battle for the nomination could end up offering more upside than downside. As one senior Democrat remarked to me earlier today, daily political combat hones campaigns. It forces them to respond and innovate and deal with crises. It pushes them out of their comfort zones. It forces candidates to make arguments and to grow.

Clinton, if she wins the nomination, could very well face either Donald Trump or Ted Cruz. Laugh all you want about Trump’s buffoonery, and scoff all you want about Cruz’s Goldwater-like extremism, but both of them are brutal and unpredictable on the attack. (Marco Rubio is said to be a political killer, too, but it’s not clear to me that we know what he’s really made of yet.) Whether it is Trump or Cruz — and quite possibly if it is Rubio — the GOP nominee will run a very tough campaign against Clinton.

Just look at what we’re seeing now. The Clinton campaign — nervous about the growing Sanders threat — is kicking things into high gear. It has been aggressively challenging Sanders’ record on guns. It released the first piece of her tax plan yesterday, a proposal to hit those who earn over $5 million per year with a tax surcharge. Per reporting from Jennifer Epstein and Jonathan Cohn, the Clinton camp today rolled out two more pieces of this plan, a call for expanding the estate tax and a call to close various loopholes employed by the wealthy.

This is a campaign that’s fighting hard. That’s a good thing for it.

To repeat, the possibility that Sanders could pull off an upset cannot be dismissed — not at all. But if she does hang on to win amid difficult circumstances, a serious, sustained and spirited Sanders challenge could make Clinton and her campaign stronger and better for it.