The main antagonist known as the President in Metal Gear Solid 2: Sons of Liberty is Solidus Snake.
Solidus Snake is the third and final known clone created from Big Boss in the Les Enfants Terribles project. He is introduced as the former President of the United States and later acts as the leader of the Sons of Liberty. His political identity and military background are both central to the game’s conspiracy.
Solidus resembles Solid Snake and Liquid Snake because all three are connected to the same cloning project, but they are distinct characters. Solid Snake is the protagonist of the original Metal Gear Solid, while Liquid Snake is the central antagonist of that game. Vamp is a separate member of Dead Cell and is not the President.
The name Solidus also reflects the series’ recurring use of “Snake” identities. In MGS2, the character’s goals, relationship with Raiden, and opposition to the Patriots make him a major link between the game’s political thriller plot and its questions about control and information.