Pilate tried to release Jesus each time they talked. Despite his efforts, he failed.
friend of Caesar: This was an official title for those, like senators, who showed great loyalty to the Roman emperor. The Jewish religious leaders implied they would damage Pilate's career by claiming he did not support Rome's interests. They probably knew that Pilate was also having a personal crisis.
Pilate’s patron in Rome, Sejanus, was the chief administrator of the empire under Tiberius Caesar. Sejanus had fallen from favor and was executed in AD 31. Pilate had every reason to be afraid.