Crossing the Potomac fell under the "Crossing the Rubicon" idiom. Nobody expected him, or the "undiciplined militia", to cross the Potomac during winter given the conditions, just as it wasn't expected that Julius Caesar would leave his area of operations by crossing the Rubicon.
I think GEOTUS is going to "Cross the Potomac"... And give us a Christmas miracle!!
Crossing the Potomac fell under the "Crossing the Rubicon" idiom. Nobody expected him, or the "undiciplined militia", to cross the Potomac during winter given the conditions, just as it wasn't expected that Julius Caesar would leave his area of operations by crossing the Rubicon.