We must not be too hasty in condemning the ‘purely political’ outlook of Sanhedrin. For in the world they inhabited, the two spheres – political and religious were inseparable. The ‘purely’ political existed no more than the ‘purely’ religious. The temple, the Holy City, and the Holy Land with its people were neither purely political nor purely religious realities. Anything to do with the temple, nation, and land involved both the religious foundation of politics and its religious consequences. Particularly of the Jewish people the temple of Jerusalem was the only existing identity symbolising their religion and their national unity. The defence of the ‘place’ and the ‘nation’ was ultimately a religious affair, because it was concerned with God’s house and God’s people.
Saying the above, I would also point out that it is important to distinguish between this underlying religious and political motivation on the part of Israel’s leaders and the specific power interest of the dynasty of Annas and Caiaphas. This dynasty of power mongers effectively precipitated the outcome of the year 70 CE and so caused precisely the outcome it had been their task to avoid. To this extent the death sentence passed against Jesus is characterized by a curious overlapping of two layers. The legal concern to protect the temple and the nation, on the one hand, and the ambitious power seeking of the ruling group, on the other.