After Bernie Sanders’ stunning victory in Michigan, we’re going to hear a lot of damage control about the delegate math. The logic goes: Clinton is up by more than Obama ever was in the delegate race, and she even expanded her delegate lead a bit because of her overwhelming victory in Mississippi. This isn’t wrong: and believe me, the delegate deficit is still a daunting hill for Bernie Sanders to climb. But the reasons to be nervous in the Clinton camp are legion. Here is why:

1. Virtually all of Clinton’s delegate lead has been accumulated from Southern states, which are nearly ALL done. The calendar was significantly in her favor. Just take a look at this map of the state results:

Keep in mind, the 3 states she “won” outside the south: Nevada (by 5), Iowa (virtual tie), Massachusetts (by 1). The comments that Clinton is a “regional candidate” that can only win in the South are a little extreme. But when you look at that map, you can see exactly how extreme this calendar has been in her favor. The only two southern states left, North Carolina and Florida, are voting March 15th by the way.

There are lots of delegate trackers out there, including from 538, which paint the picture that Sanders is missing his targets. But he is only missing his targets in the south. If you average all the other states, he’s actually beating them on average (yes, there are a few counter examples, including Iowa) — And he seems to be accelerating his pace of beating the targets, having met or exceeded every target since super tuesday except for Louisiana and Mississippi (two deep south states).

2. There is growing evidence that Sanders may be outperforming his polling, sometimes significantly, outside the south (and underperforming in the south). Michigan is obvious: This is a polling miss that will be studied for a long time, almost unprecedented in modern politics. But recall he also significantly outperformed his polling in Massachusetts. He less significantly outperformed it in Iowa, New Hampshire. For the super tuesday states, we lacked polling in Minnesota and Colorado, but one of the only public polls of Minnesota (Mason-Dixon) had Clinton up by 30 — He won by 24. No Oklahoma poll had him winning by as much as he did, and several more had him losing. The one public Kansas poll had him down 10, and he won by 35.

So what happens in Ohio, an open primary, where polls have had similar results for Clinton as Michigan did (actually, less optimistic even). What happens in Missouri? What about Illinois, another open primary? We’ve heard that the polls suggest Clinton is going to be huge on March 15th, but at this point I’d really start to question a LOT of assumptions about the electorates in those states. Does anyone really believe Hillary will win Ohio by 20 if she lost Michigan?

3. This might be the most favorable media coverage Sanders has received. We’ve talked a lot about momentum — A lot of Sanders fans had staked their chances on a big win in Iowa, which would start the momentum train. The same thing was hoped for in Nevada. He came up just short in both — And since then, Clinton has had all the favorable news cycles with big wins on Super Tuesday, South Carolina, etc.

All this is to say that if Sanders is going to make a run in the national polls (and hence in future states), it could happen this week. These are the frontpage stories that Sanders needs:

4. After March 15th, it is conceivable Sanders could win eight states in a row. While there will still be a big delegate margin to make up even if he does, it is difficult to overstate how much momentum could be derived from this. Could he make a run in Pennsylvania? Its a closed primary, which will limit him a bit more, but if he really does win state after state, you just never know.

Moral of the story is this: Clinton is still a strong favorite to win. But if Sanders can do well on March 15th: Perhaps winning Ohio and Missouri, keeping it relatively close in Illinois, and limiting the damage in North Carolina and Florida… he could wind up in a position stronger than most of us assumed before the stunning Michigan result.

It will be an uphill climb. But really, if he was able to overcome a polling average showing him 20 points down, in a state where there was a rich amount of polling… I would not write him off anywhere.