You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
University_of_Notre_Dame

Context:
In the film Knute Rockne, All American, Knute Rockne (played by Pat O'Brien) delivers the famous "Win one for the Gipper" speech, at which point the background music swells with the "Notre Dame Victory March". George Gipp was played by Ronald Reagan, whose nickname "The Gipper" was derived from this role. This scene was parodied in the movie Airplane! with the same background music, only this time honoring George Zipp, one of Ted Striker's former comrades. The song also was prominent in the movie Rudy, with Sean Astin as Daniel "Rudy" Ruettiger, who harbored dreams of playing football at the University of Notre Dame despite significant obstacles.

Question:
Ronald Reagan had a nickname, what was it?

The Gipper