As for your question thus:
"That's interesting. There seems to be a tension: you stated the kingdom is within unbelieving Pharisees and also recongized they hadn't yet entered it. How can something be in you if you haven't yet entered it?"
A good question. Jesus said both. He told them the kingdom was within them and yet also told them they had not yet entered in. I believe this means that even though they had the kingdom "planted" inside their own hearts, they had never entered into that place inside themselves where the Lord was present and reigning. Jesus was "knocking on the door", but they hadn't yet entered through the "narrow gate". It's an inner spiritual journey that they were unwilling to take because they were too focused on the carnal physical elements of the world.
Each man must make that same inner spiritual journey to the kingdom that is within them, entering through the narrow gate, and opening the door to Jesus who is knocking. When a person does this they become "God conscious", and they realize that it is Jesus who has been there all along. When they embrace Him and believe His testimony in their heart, thereby repenting and walking in His steps.....they enter into the kingdom that is inside them...because they enter into the place in their spirit where Jesus is truly Lord and Master.
That's what I believe.