LD and PF---
Speak clearly and distinctly with articulation and enunciation in a relaxed but informative style. Avoid didacticism, preachiness, and condescending tones.
Facts and stats (Ethos and Logos) are necessary; however, humanize Facts and Stats with real-life human conditions and results (Pathos).
Speaking quickly to spew out a flow of Facts and Stats will not win the day. Rather, speak with confidence, be assertive, be declarative, and present your case with genuineness and sincerity.
Don't attack your opponent. Raise doubt in your opponent's reasoning and logic without demeaning your opponent.