Here is the section I transcribed from that Rabbi Mizrachi lecture where he answers the question "Why do most Rabbis fear telling the truth like Rabbi Kahane told the truth?"
1:13
Rabbi Mizrachi:
You mention Rabbi Meir Kahane
Rabbi Kahane was very strict, he spoke the truth in the face of the Arabs
He wasnt one in his heart, one in his mouth
Everything he thought he was saying in their face.
They used to come to his lectures and argue with him
And he told them in their face, "The land doesn't belong to you!"
"It belongs to us, we're doing you a favor that we are willing to pay you to leave the land."
How many people were against him.
What was his end?
He got killed.
Why?
Because the people who say the truth sometimes they pay a heavy price for it.
But I want to give you another example.
The prophet Yishaiah , one of the greatest prophets we had.
What happened to him?
Got killed by his own grandson.
His grandson was a wicked king. Menashe.
He sliced him to slices with the sword
You understand why? Because he told him the truth.
Baruch Hashem it hasn't happened to me yet.