I don't think I'm alone when I say that I've often heard about the fickleness of the crowd that shouted "Hosannah!" in this passage, quickly turning to shouts of "Crucify him" only a week later. It turns out that this is likely a theological myth.
Click here for the entire post, but I will just include the ending summary......
So let the joyous news be spread! The crowd was not fickle. And did not praise him one day and cry out for his murder another. Two crowds were coming and going all week. Both grew stronger in their conviction as the week went along. The sheep grew sheepier. And the goats grew goatier. The later group conspired to work around the former. Later on, Peter referred to this group as “lawless men” (Acts 2:23). This better fits the crowd of chief priests, scribes, elders, Pharisees, who could act against the law and above the law, and get away with it. Regular folk lack such power in general.
So let us join in the singing; and stand with the blind, the lame, the disciples, the children, the Cyrene, the women who later stood at a distance and look bewildered at the cross, and the general populace, who at this moment saw the truth, at least in part. “All glory laud and honor to thee, Redeemer King. To whom the lips of children make sweet hosannas ring.” Sing with them and do not diminish their child-like faith with talk of fickleness.
Tomorrow's Bible In a Year Passage: 1 Samuel 19-21, Luke 20