Sorry, FRiend, but the Roman plaque, "The King of the Jews" on Jesus' cross proves beyond any reasonable doubt that Romans did not crucify Jesus for blasphemy.
The Romans couldn't care less about such things.
Then you accept that historical account? The same historical accounts prove beyond any reasonable doubt that the Sanhedrin asked Jesus to be put to death for blasphemy.
The reasons given for political acts are often just rationalizations, and the real reasons not admitted. Historical accounts are subject to selective omission or outright revisionism. Ultimately, no one knows for sure.