The Sadduccees, Pharisees and Essenes are the three main groups in Israel at this time (although the Essenes are not mentioned in the Bible). The Sadducees were a group of wealthy, aristocratic people who maintained control over the Temple. In contrast, the Pharisees were more working class in nature while the Essenes were a breakaway group opposed to (“disgusted with” is the term used at Jewish Virtual Library) both the Sadducees and Pharisees and who lived apart from both groups. The Sadducees believed in a strict literal interpretation of written Scripture while the Pharisees followed both an oral tradition and the idea that the written Scripture was intended to be interpreted by man. Pharisees believed in a resurrection of the dead and an immortal soul. The Sadduccees did not believe in either.
Mark 11:27 They came again to Jerusalem, and as he was walking in the temple, the chief priests, and the scribes, and the elders came to him, 28 and they began saying to him, “By what authority do you do these things? And who gave you this authority to do these things?” 29 Jesus said to them, “I will also ask you one question. Answer me, and I will tell you by what authority I do these things. 30The baptism of John–was it from heaven, or from people? Answer me.” 31 They reasoned with themselves, saying, “If we should say, ‘From heaven;’ he will say, ‘Why then did you not believe him?’ 32 If we should say, ‘From people'”–they feared the crowd, for all held John to really be a prophet. 33 They answered and said to Jesus, “We do not know.” Jesus said to them, “Neither do I tell you by what authority I do these things.” NHEB
These are the men in charge of the spiritual well being of Israel and the ones most offended by what Jesus did in the Temple. They ask about His authority to do these things (apparently they have not been paying attention). In Mark 1:16, Jesus tells Andrew and Peter to follow Him and they do. Same thing for James and John. Why would they leave their homes, families and work unless there was something special about this guy? They move on the Capernaum and these new disciples are astonished at how He teaches with authority (unlike the scribes). Jesus then casts out a demon who recognizes Him as the Son of God. What we see from the beginning is that He has the authority to tell people to follow (and they do), the authority to teach and the authority to cast out demons. He forgives the sins of a paralytic before healing him. Everything Jesus does is an extension of His authority yet we see Jewish leadership questioning this authority even to the point of suggesting that He is an agent of the devil.
When asked about that authority, Jesus doesn’t answer directly but points to baptism by John (which is where His ministry begins and where He is declared to be the Son of God). They understand from the Temple cleansing that Jesus has taken a swipe at them and is setting them aside.
Mark 12:1 Then he began to speak to them in parables: “A man planted a vineyard. He put a fence around it, dug a pit for its winepress, and built a watchtower. Then he leased it to tenant farmers and went on a journey. 2 At harvest time he sent a slave to the tenants to collect from them his portion of the crop. 3 But those tenants seized his slave, beat him, and sent him away empty-handed. 4 So he sent another slave to them again. This one they struck on the head and treated outrageously. 5 He sent another, and that one they killed. This happened to many others, some of whom were beaten, others killed. 6 He had one left, his one dear son. Finally he sent him to them, saying, ‘They will respect my son.’ 7 But those tenants said to one another, ‘This is the heir. Come, let’s kill him and the inheritance will be ours!’ 8So they seized him, killed him, and threw his body out of the vineyard. 9 What then will the owner of the vineyard do? He will come and destroy those tenants and give the vineyard to others. 10 Have you not read this scripture:‘The stone the builders rejected has become the cornerstone. 11 This is from the Lord, and it is marvelous in our eyes’?” 12 Now they wanted to arrest him (but they feared the crowd), because they realized that he told this parable against them. So they left him and went away. NET
Jews hearing this parable would think of Isaiah (and of Israel as God’s vineyard) and understand this as a reference to Israel. The tenants in this parable are the chief priests, scribes and the elders. The vineyard owner sending servants equates to God sending prophets who call Israel to covenantal faithfulness. He finally sends a son.
Verse 9 is one of the bases for the notion of supersessionism/replacement theology but be careful not to read something into the text that is not really there (eisegesis). This is why Romans 9, 10 and 11 are so important as the way to put all of this into context. The Jews have refused to do what they were assigned to do so the work has been transferred to others. The agency by which God will accomplish His purpose has changed from one group to another but make no mistake, we are in trouble if God doesn’t keep His promises to the Jews.
So the tension is rising and the plot is thickening because Jesus is critical of the system and is subverting everything the Jewish leadership is doing. The San Hendrin is focusing on blasphemy since Jesus says He is going to destroy the Temple.