What is the name of the Republican presidential candidate in the final season?

The Republican presidential candidate in the final season of The West Wing is Arnold Vinick.

Vinick is a fictional senior senator from California, played by Alan Alda. A moderate Republican, he wins his party’s nomination during the sixth season and becomes the central Republican figure in the seventh season’s 2006 presidential campaign.

Vinick runs against Democratic Congressman Matt Santos, played by Jimmy Smits. His campaign emphasizes experience, fiscal restraint, and a more centrist approach, but his support for nuclear power creates political problems after an accident at a California plant. He chooses West Virginia Governor Ray Sullivan as his running mate.

The election is ultimately won by Santos, who defeats Vinick 272–266 in the Electoral College. Vinick later accepts Santos’s offer to become Secretary of State. Common mix-ups include confusing him with Glen Allen Walken, another Republican figure, or with Santos, who is the Democratic nominee.