A man who has a crucial, often hazardous role in the forefront of an enterprise.
The administration's point man on health care.
Anyone in the forefront of an activity; esp., someone leading an attack on or a movement in support of some proposed program, as in politics.
Webster's New World
(military) In combat, the soldier who takes point; the soldier who assumes the first and most exposed position in a combat military formation; the lead soldier/unit advancing through hostile or unsecured territory.