What do you call a person who is skilled in the art of writing or speech and argues cases forcefully?

A polemicist is a person skilled in the art of writing or rhetoric who often engages in contentious or forceful arguments. This term highlights an individual who not only argues but does so with a particular emphasis on persuading others, often on controversial topics. The use of "polemic" suggests a person who is adept at using rhetoric to defend their position or challenge opposing viewpoints, making it the most accurate choice for someone who skillfully argues cases.

While the other options may suggest related skills, they do not encapsulate the full force of argumentation implied by "polemicist." An orator is primarily noted for their speaking skills but may not necessarily engage in argumentation. A debater, while involved in structured arguments, may not have the same connotation of engaging in heated, contentious discourses as a polemicist does. Argumentative, on the other hand, describes a tendency to argue rather than a specialized skill in persuasive writing or speaking. Thus, "polemicist" is the most precise term for someone who excels in forceful advocacy through writing or speech.