Answer:
The terms that describe the bracketed portion of the sentence are the following ones: Nonrestrictive and clause.
Explanation:
"Who is running for mayor" is a nonrestrictive relative clause. This clause is nonrestrictive or nonessential because the information it provides is not considered necessary to complete the meaning the meaning of the sentence or to identify the noun it modifies. If the clause was removed, the meaning of the sentence would be unchanged (see 1).
1) Sayeed Johnson will be speaking at the city library tonight.
