Some people are picking up very old threads. Does that necessitate reading them over again to see what's what?
Guinevere's quote is excellent for pointing out the significant effect of Gandalf's presence, the inspiring sense of hope. It is a very Obama-like situation. And
Strongbow--welcome to the Downs--will your posts be as a good libation?--is spot on that Gandalf does not operate to gain power for himself.
Yet in so many other situations Gandalf did not inspire hope, but suspicion. What changed to bring hope into Gandy's presence here and now at the Seige?
by the by, it is interesting to note that Denethor does not seem to acknowledge the White in Gandalf, as Denethor calls him the
Grey Fool.