Before nominating someone for an open seat on a federal district court in wisconsin, the president consults with the senator from wisconsin who shares the president's party label. this is an example of what?

The correct answer is senatorial courtesy

When you consult with senators from the state then that's called senatorial courtesy. It has been a common practice in the history of the United States of America, even though it's not a written thing or a thing mandated by any type of legislature.