In this week’s 2016 Slack chat, the FiveThirtyEight politics team contemplates the “Bernie Bump.” As always, the transcript below has been lightly edited.

micah (Micah Cohen, politics editor): Last week was a pretty good one for Bernie Sanders. Polls came out showing him closing in on Hillary Clinton in Iowa, and he continues to lead in New Hampshire. Weirdly, there wasn’t any obvious piece of news that would explain a Sanders surge. So, is it real?

natesilver (Nate Silver, editor in chief): It seems pretty clear that he’s gained ground in Iowa. Less clear in national polls. Somewhere in between in New Hampshire.

harry (Harry Enten, senior political writer): Well, I’m not sure he’s gained ground in Iowa as much as Clinton has lost ground, according to the Des Moines Register poll. It is clear that the race is tighter in Iowa. Nationally, I do think Sanders has gained, but Clinton still holds a rather clear lead (15 to 20 percentage points). In New Hampshire, Sanders is ahead, but is it by 5 or 10 percentage points? I don’t know.

clare.malone (Clare Malone, senior political writer): I think that people started looking more seriously at Sanders in December, and I’m not really sure why. Maybe it was his campaign ramping up advertising in early states, being in the news more for the data breach (not that that was a good thing for Bernie, but he did try to spin it into “the DNC is trying to mute me”). Who knows! But he’s now being talked about as a serious candidate, where for a while he was sort of being treated more in the vein of a Dennis Kucinich.

natesilver: FWIW, our FiveThirtyEight national polling average (which we’re not publishing yet — stay tuned) has Clinton up 22 percentage points. Although that was before the Monmouth poll released today, which might tighten things a bit. But somewhere in the high teens or perhaps low 20s nationally is where the race seems to be. By contrast, our averaging method would have had Clinton up by 25 points at the end of December.

So that suggests some tightening, but not as much as the media narrative — which is pretty blatantly cherry-picking which polls it emphasizes — seems to imply.

micah: But this, at least in Iowa, doesn’t seem to be a case of “the media is making all this up.”

natesilver: Indeed — our Iowa polling average now has Clinton up by 5 points, compared with 16 points at the end of December.

harry: Well, the most recent NBC News/Wall Street Journal poll found Clinton gaining over Sanders nationally.

micah: Does anyone have other explanations for the tightening in Iowa? Just more people tuning in? Change in tone of the media, as Clare said?

harry: How about the fact that Sanders has been outspending Clinton on television advertisements?

clare.malone: I think there’s probably a lot of that, and I also think there’s something to be said for the fact that people like Bernie’s idealistic version of the Democratic Party. But that’s also the luxury of being a voter in an early state, right? They feel like they can champion a guy who might not be mainstream but who can change the tenor of the race a bit. Whereas someone who’s voting in March might be more inclined to think of his vote in pragmatic terms — who’s going to actually win the general election?

natesilver: In Iowa, the demographics are pretty good for Sanders — as good as in New Hampshire, pretty much. He has a good ground game. People don’t have a lot of reason not to vote for him. The phrase “natural tightening” can be pretty meaningless, but I think it applies reasonably well here.

harry: Indeed, the favorable ratings for Clinton and Sanders are nearly identical in Iowa. Voters like both candidates. It’s doesn’t take a lot for them to shift between the candidates.

micah: And I think Clare’s right that the tone of the coverage of Sanders has shifted: People are taking him more seriously now.

clare.malone: The race getting tighter in Iowa has a lot to do with more people leaving the Clinton camp and saying that they’re undecided, so there’s still time for them to run back to her, but also just as much time for the Bernie momentum narrative to continue, which is helped along by … media like us! Slack chats changing the course of history, guys. This is big stuff.

harry: YUGE STUFF!

natesilver: Would you rather be the candidate (Sanders) whom the media ignores or the candidate (Clinton) whom the media interprets everything as being bad news for?

clare.malone: Ooh, primary election “would you rather.” This could be a MILLION-DOLLAR IDEA.

micah: The media doesn’t ignore Bernie.

clare.malone: I would always rather be the underdog, aka Bernie.

micah: I’d rather be Martin O’Malley.

clare.malone: Managing your expectations is key in politics, as in life.

natesilver: Our data suggests that Sanders is a little under-covered relative to his standing in the polls.

micah: That data is old.

clare.malone: SNAP!

harry: Micah throwing da shade.

micah: All right, so let’s posit that the tightening of the race in Iowa and (to a lesser extent) the nation is real and lasting. Sanders leads in New Hampshire. Is Sanders a real threat to win the nomination now?

natesilver: Define real.

clare.malone: I think that’s definitely going to change over the next week or so. The New York Times had a big piece this morning about how the Clinton campaign is changing its strategy given the Bernie bump (which, incidentally, sounds like a really fun dance move, no?).

harry: My New York accent is real. My ability to drive is also real, but not really real.

micah: Real means >25 percent chance.

natesilver: Sell.

micah: 20 percent.

harry: Sell.

natesilver: Still selling.

micah: [let’s give the #feeltheberners a moment to leave an angry comment]

15 percent.

natesilver: That’s about where Betfair has it, for what it’s worth.

harry: I’m sorry, but — knowing I’ve been paid off by my corporate overlords — here’s what I see: There’s just little-to-no sign that Clinton has lost any traction among black voters. The most recent YouGov poll has her up 75 percent to 18 percent among black Democrats. The most recent Morning Consult poll has her ahead 71 percent to 14 percent. The most recent Monmouth poll has her up 71 percent to 21 percent among non-white voters. Sanders would need to close that gap to have any chance in South Carolina. And remember, Clinton was only up by 7 percentage points at this point among non-white voters in the 2008 cycle.

natesilver: Indeed. That, along with her support from the party establishment, is why Clinton is the heavy favorite. But at what point does the price on Bernie become attractive to you?

If I could get him at 20-1 (implying about a 5 percent chance of winning), I’d take it.

harry: Yes. I think that’s fair.

clare.malone: This is a real down-at-the-betting-window Slack chat, isn’t it?

micah: Here’s the real question for me. For Sanders to win the nomination, he probably needs to win Iowa AND New Hampshire. And that’s eminently possible.

But if that happens, how much does that reset the race? You can imagine the media shitstorm that would follow, but is that shitstorm enough to hurt Clinton with non-white voters?

clare.malone: No, I don’t think so, Micah. Those are two pretty white states, right? I think Clinton would still be able to make her broad appeal, and, sure, she might have to do some big rebranding, maybe hitting heavier on a progressive economic message, playing up the whole thing about how Bernie is going to dismantle Obamacare, etc. — that to me, from the looks of the debate, is going to be one way that she hits him, gets the message across that he’s more “pie in the sky” idealist than “get it done” politician.

natesilver: Yeah, I think he needs both. Given its demographics and how much voter enthusiasm matters in a caucus, Iowa should be among the easier states in the country for him to win. If he can’t win in Iowa, I don’t think he’s competitive in enough places to make it a real race, although he could still win New Hampshire.

As far as forecasting the severity of the shitstorm, I’m of two minds. On the one hand, the media will absolutely eat up the story of the “inevitable” Clinton losing Iowa to a septuagenarian self-described socialist. On the other hand, Clinton’s media coverage is always something of a shitstorm. With a few exceptions, the Beltway consensus for months was that Joe Biden needed to jump into the race because Clinton was doomed. That proved to be profoundly flawed. And it depressed Clinton’s numbers in the polls, but not to the point where she ever trailed Sanders.

harry: Here’s what Sanders needs to do: Win caucuses out West (and polling out there suggests he could do so) and some Northern primaries. Then, he needs to combine that with doing better in the outer South (Kentucky, Oklahoma, Tennessee, West Virginia) than President Obama did. That’s the way this works. He won’t be able to recapture the Obama coalition in the Deep South.

micah: Are you all surprised that Sanders has gotten this close?

clare.malone: I don’t think it’s really all that surprising. I actually think, as crazy as it might sound, that Donald Trump and Sanders are trying to appeal to similar forces fomenting in the American population; people are frustrated with the way things are going, they are skeptical of big institutions (banks!), and they want to see a different kind of leadership. Of course, Trump’s way of courting this is instilling fear in people, and Sanders’s way of courting this is righteous, idealistic governmental revolution. They’re both populist movements, albeit with undertones of authoritarianism in one.

natesilver: I don’t think it’s that surprising. First, as we’ve been saying for six months now, the first two states happen to be pretty favorable for Bernie.

Second, there are a lot of people, including the media and Democratic interest groups, who have a strong incentive for there to be a competitive Democratic race, or at least some semblance of one. To get a little more wonky still, the median voter theorem would imply that two-candidate races should be at least reasonably close.

Third, history suggests that even “inevitable” candidates, like Bob Dole ’96 and George W. Bush ’00, lose a few states. Al Gore ’00 was the only one to sweep all 50. But he nearly lost New Hampshire to Bill Bradley. And if you’d read the press coverage of that race 16 years ago, you’d see plenty of articles about how Bradley was surging and it was time for Gore to panic.

harry: Sure, and both Dole and Bush used South Carolina as a firewall, just as Clinton might.

natesilver: Maybe this is all coming out as more skeptical about Bernie than I’m intending it to be. The case for Bernie is that (i) he could win Iowa and New Hampshire, which (ii) could produce huge momentum and very favorable press coverage, and (iii) he has enough money and a good enough ground game to run a long campaign, and (iv) well then, who knows, maybe this time really is different?

How do you translate that into a probability? That’s difficult. There’s a reason we’re trying to model the primaries one state at a time, instead of issuing an overall forecast.

harry: We won’t know if Bernie is for real until he wins Iowa. If he does, then let’s see where his support with non-white voters goes. Until then, it’s a lot of hypotheticals. And I’ve found that this season, hypotheticals have a weird way of playing out.

Check out the latest polls and forecasts for the 2016 presidential primaries.