The underlined portion of the sentence is described first by the term The parto of the sentence that is appositive is in between commas.The second term is clause.The part that is underlined is called a because it gives additional information about the main clause.
"who is running for mayor" is a nonrestrictive clause. This is not an appositive phrase because it is not simply a noun that replaces or renames another noun. A nonrestrictive clause contains a subject and verb and contains nonessential information. It is set off by commas. In this sentence the nonrestrictive clause is "who is running for mayor". It contains the subject "who" and the verb "is" to describe who Sayeed Johnson is. A restrictive clause is begins with "that" and contains necessary information.
