A lady on FB posted about how great the speech Obama gave was. i asked her for one thing in it she thought was particularly good, and she responded "Hope.".
OK, then. Hope. Some politician gave a speech about hope, and maybe zoning (though I couldn't find that in the transcript I scanned).
How many speeches in history have had some lingering impact? Even the Gettysburg Address was largely panned at the time, in part for being too short (which I'd view as a plus). I think the Churchill speech in the HoC had impact. I'd opine 99.99% do squat, maybe a very brief "Wow, great speech!" comment by partisans, and a week later they couldn't tell you anything about it.
Sound and fury ...
Conventions are to gin up the base, and get the powers that be together to sort out who is going to gran that Ambassadorship to Peru et al. A President makes over 4,000 appointments, I've read, nearly all of which are PLUM assignments, worth donating however much money one can manage to snare one. Secretary of Commerce? Assistant Secretary? Assistant to the assistant associate Secretary of Homeland? Brigadier general?
All the judgeship positions? Not just SCOTUS, but all the myriad others.