Final answer:
Erin’s confidence before going on stage could stem from thorough preparation, a well-researched speech, and a clear message, all of which can boost a candidate's self-assurance in a debate setting.
Step-by-step explanation:
The question relates to why Erin feels confident before going on stage. Based on the information provided, elements such as having a well-prepared and researched speech, being at ease due to solid preparation and confidence, and possessing a clear message are important for a candidate to feel confident before a debate. The specifics of why Erin feels confident aren't provided in the provided reference text, so we cannot definitively choose an option. However, the reference material suggests that a candidate, like Erin, would feel confident if they had prepared well, understood the importance of maintaining a positive on-camera presence, and had a clear message to convey.