The Passover was always a time when national feeling was ready to blaze up, and any spark might light the fire.
It looked as if the resuscitation of Lazarus was going to be the match this time.
Plus Jesus was such a controversial Person that it was impossible for Him to be near Jerusalem and remain unnoticed. From all over the country, people came to the Passover feast.
And so When the crowd met him shouting "Blessed is He who comes in the name of the Lord" it became the catalyst that sealed the coming events of the crucifixion.