From a pastor in the United Presbyterian Church:

Jonah-
Concerning your post on this scripture reference and the subject of guilt for Christ’s crucifixion, there are a couple of things worth mentioning.
1. The words of the crowd must be tied not only to Jesus’ fate, but to the fate of Barabbas. If we are to imagine a crowd (at least some of whom are gathered to hear of and possibly influence the selection of the prisoner who would receive paschal amnesty), and realize that they are confronted with the choice of Jesus or Barabbas, it seems likely that any faltering on the part of the crowd would be influenced by their leaders – which is what Matthew’s account makes clear.
2. Even if there is a symbolism that the crowd’s response reflects the response of an even greater majority of the nation, Matthew undoubtedly knew that all the first disciples of Jesus were Jews. It is only when Matthew’s gospel is read not as a description of Jesus’ trial, but of later church-synogogue relations that it can be forced into the framework of anti-Semitism.
3. Because the first disciples, and indeed the entire nascent church are ethnically Jewish, the kind of opprobrium which is found directed at various Jewish people (whether leaders or crowds) must be seen to be in line with the writings of the prophets in the Old Testament. In the prophets the people are both the object of compassionate pleading and virulent warnings.
4. Finally (and yes, I owe you an aoplogy for making this “couple of things” into four points), about the words themselves: they may well be not simply a double-entendre, but a triple-entendre. The Christian message is that all who are guilty before the Living God of and complicit in the death of his Son (meaning all of us without exception), still may have the prospect of being forgiven and transformed by what Christ accomplished on the cross.
This has been a rather long note. Thanks for reading. Thanks for your columns and Corner postings