Earlier this week, we officially crossed the halfway point of the race for the Democratic nomination. After the 13 delegates from the “Democrats Abroad” primary were awarded on March 21st, at total of 2031 pledged delegates had been decided, leaving 2021 delegates still up for grabs.

After adding the results from the primaries in Arizona, Utah and Idaho on Tuesday, the race is up to 2162 pledged delegates won, with 1889 left to be decided in the remaining contests between now and the end of June.

While the media has tried to downplay his chances of securing the nomination, Bernie continues to surprise the pundits by racking up big wins throughout the Northeast, the Midwest and the Western states. Recently the pundits have settled on a new rationale for Hillary’s inevitable coronation as the Democratic nominee: Namely that “the math” simply will not allow Bernie Sanders to secure the nomination.

In this post, I’d like to dig a little deeper into what “the math” really looks like and what the numbers really say about Bernie’s chances of overtaking Clinton to win the nomination.

Here are the key figures to know:

There are total of 4051 pledged delegates available in all of the Democratic primaries. In order to clinch a majority of pledged delegates, a candidate must win at least 2026 delegates.

pledged delegates available in all of the Democratic primaries. The Democratic Primary also includes 712 “Superdelegates” which vote at the Democratic National Convention held at the end of July. There are several reasons why I do not believe that superdelegates will sway the nomination away from the winner of the pledged delegates. I’ll cover the reasons for this in a separate post but for right now, you should know that whichever candidate wins a majority of pledged delegates is by far the most likely become the Democratic nominee.

“Superdelegates” which vote at the Democratic National Convention held at the end of July. There are several reasons why I do not believe that superdelegates will sway the nomination away from the winner of the pledged delegates. I’ll cover the reasons for this in a separate post but for right now, you should know that At the time of writing (March 24th), Hillary Clinton has banked a total of 1229 pledged delegates, while Bernie Sanders has won 933 .

pledged delegates, while Bernie Sanders has won . As of today, there are 1889 pledged delegates still up for grabs in the remaining primaries.

pledged delegates still up for grabs in the remaining primaries. Delegates in all the Democratic primaries and caucuses are allocated proportionally. Unlike the GOP race, the Democrats do not have any “winner take all primaries” so delegates in each primary or caucus will be awarded roughly in proportion to the vote in each state or territory.

So what do the numbers above say about Bernie Sanders chances of securing the nomination?

In order to clinch a majority of pledged delegates, Bernie needs to win an additional 1093 delegates from the remaining contests. That means he needs win just under 58% of the delegates still outstanding (1093/1889 = 57.86%).

Note that the 58% target refers to the number of delegates, not the number of actual votes. The percentage of delegates awarded in each contest is based upon a formula that it not exactly proportional to the percentage of total votes, but in most instances the numbers come out pretty close.

So the easiest way to keep track of how Bernie is doing in the upcoming primaries is to keep this 58% number in mind. If Bernie wins by 58% or more, that keeps him ahead of pace to win the nomination. If he wins by less than 58% (or loses), that means he is falling behind.

This weekend, there will be 142 delegates at stake in Washington, Hawaii and Alaska. Bernie will be looking to win at least 83 delegates on Saturday to stay on pace towards winning the nomination (83/142 =58.5%).

Note: I recommend keeping tabs on how many delegates are awarded using FiveThirtyEight’s delegate tracker, which does not include superdelegates. Most other media outlets I have seen have problematically lumped superdelegates and pledged delegates together, providing an exaggerated view of Clinton’s lead.

Obviously this 58% target figure will go up or down after each primary as Bernie does either better or worse in each contest. (I’ll try to provide an updated target percentage after each major primary or caucus for those who wish to follow along.)

So how likely is it for Bernie to win 58% of the remaining delegates?

As I mentioned in my review of the race following Bernie’s “upset” win in Michigan, the outcomes in race thus far have mostly split on differences in regional strength between the two candidates.

Hillary Clinton has won handily in conservative, GOP-dominated states across the south, while Bernie has posted big wins in the Northeast, the Midwest and the upper Western half of the country:

Errata: In a previous version of this article, I failed to fill in Clinton’s win in Nevada.

As you can see, Hillary has not fared very well in primaries north of the Mason-Dixon line. Her only significant win so far has been in Ohio, where she won 56% of the pledged delegates. Iowa, Massachusetts, Missouri, Illinois were decided by razor thin margins that left both candidates essentially tied in the number of delegates awarded.

If this trend holds, Bernie is poised to do very well going forward, as there are very few southern states left on the map, and lots of western states like Washington and Oregon where he is poised to do very well. There are also lots of Midwest/Eastern states on the board where he should be in strong position to compete.

The Clinton camp may start showing withdrawal symptoms as the primary season heads north.

Of course, there is still a long way to go and Hillary Clinton will be competing very hard in the states that are left. The main states where Clinton will be looking to do damage are New York, New Jersey and Pennsylvania. Obviously, Clinton will have homefield advantage in New York, the state she represented in the Senate from 2000–2008 (and likely lots of pro-Clinton dollars flowing out Wall Street).

Clinton needs big wins in New York (247 delegates) and probably neighboring New Jersey (126) in order to cut off Bernie’s path toward the nomination.

Hypothetically, if Clinton were to win New York and New Jersey by a combined margin of say 65%-35% — Bernie would have to win all the other contests by an average of 64% to clinch the nomination — a pretty tall order. However, if Bernie holds wins New York and New Jersey or at least holds them to a near tie, then his path to victory remains open.

My hunch is that going forward we will see each of the candidates try to double down on the areas where they are strongest. Bernie will try to build a cushion with big margins in Western states like Washington (101 delegates) and Oregon (61 delegates), while Clinton will focus most of her efforts on New York, New Jersey and Pennsylvania in an effort to protect her lead.

On a final note, its almost certain that the Democratic race will go all the way to end of the primary season.

The race is simply too close for either candidate to clinch a majority of pledged delegates without the 714 delegates that will be up for grabs on June 7th. (For Clinton to clinch a majority of pledged delegates before June, she would have to win close to 70% of all delegates up for grabs between now and then.)

That means that there is almost no chance that Bernie Sanders will drop out of the race before the primaries are over. So whatever happens between now and then, we’ll almost certainly be looking at a fight to the finish.