Joe Biden's national lead is fundamentally weak.
Why is that noteworthy?
Hillary's support was MUCH more firm, enough to sustain a loss or two in early states ahead of more diverse primaries.
Ultimately, using a gimmick & Martin O'Malley, Hillary won Iowa Caucuses.
He can't safely lose IA & NH.
Bernie Sanders isn't "just now" reaching out to those voters. Same is true in Arizona.
If I'm the Biden Campaign...
The calendar is different. If they split early states he could EASILY lose California to Bernie.
That's not debatable anymore. It's reality.