(CNN) First things first: The theme song of the week is the closing credits to Baywatch .

A new CNN/SSRS poll shows that former Vice President Joe Biden leads the Democrats among potential Democratic voters nationwide with 28%. Vermont Sen. Bernie Sanders and Massachusetts Sen. Elizabeth Warren are in a fight for second at 17% and 14% respectively. South Bend, Indiana, Mayor Pete Buttigieg comes in fourth at 11%.

Other national polling shows Biden with a clear advantage on the Democratic field.

Biden is steady as a rock in national polling. As I noted earlier this week , he's been within the margin of error of 30% in all but two CNN/SSRS national polls. Yet, it always seems that his opponents (and some members of the press) are just waiting for him to collapse.

Biden could eventually falter, but it seems to me that those counting on it just aren't talking to enough older black voters.

Biden's averaged 49% among all potential black Democratic primary voters in our last two CNN national polls. That's good enough not only for a 35-point lead over his Democratic competitors, but good enough to beat all of them combined by about 10 points.

But I think treating black voters as if they're some sort of monolith creates some sort of a blind spot for those following the campaign: the wide faultline along age in the black community.

In our polling over the last two months, Biden is getting northward of 60% of the vote among black voters 45 years and older. His nearest competitor, Warren, is 50 points behind him.

Younger black voters are far less enthralled with Biden. A look at our polling over the last three months has him in the low 30s with black voters under the age of 45.

This large age gap has existed all primary long , and it's not going away. If anything, our polling is indicating that it is getting larger.

The age gap in Biden's support benefits him in a way that I'm not quite sure folks understand. Simply put, there are more older black voters than there are younger black voters. Those 45 years and older made up 60% of all potential black primary voters. In the majority black primary in South Carolina, those 45 years and older were 71% of all actual primary voters in 2016

I cannot help but think this age divide imperils some folks ability to understand Biden's appeal with black voters. If all you're reading about is how a lot of younger black activists don't like Biden ( which is true ), you're missing most of the black voting population. This is also true if you're someone who gets their news off of Twitter , where younger voices dominate in a way they don't in the real world.

Indeed, I would argue that Biden's standing with older black voters is historically strong. Looking back over the past 40 years, the only candidates with anywhere near the sort of edge with older black voters at this point in the primary that Biden has were Jesse Jackson in 1988, Al Gore in 2000 and Hillary Clinton in 2016.

All three of these candidates went on to easily win older black voters. Clinton and Gore would win the primary overall.

It's Jackson, though, who may be an interesting comparison to Biden. While the two are certainly very different (e.g. Jackson was the first black candidate to win a substantial number of primaries), Jackson held onto his black support even after performing poorly in the mostly white states of Iowa and New Hampshire.

No one knows if Biden can maintain the backing of older black voters if he loses in Iowa and New Hampshire, but Jackson showed it can be done.