> Federalist 10 describes factions as the nature of man, explains why they don't belong in government, and describes how the Constitution limits the sway of factions.Unfortunately, its claims in this regard were proven false not much more than a decade after it was published.
*> the Founding Fathers never envisioned it would be possible to coordinated across a continent in real time.
This would be a valid argument if factions did not become central to US politics until rapid communication became available. But that's not the case. Factions were already central to US politics by 1800, when the fastest mode of communication was horseback.