Tolerance of intolerance violates the law of noncontradiction.
It’s common to hear the intolerant attempt to paint the tolerant as hypocrites for not tolerating their intolerance. This is a cheap rhetorical trick that while it convinces nobody, can often confuse an argument. And there’s a strong logical foundation for intolerance of intolerance, especially for a philosophy of tolerance. It’s called the law of noncontradiction; simply stated, it says that you can’t have both “A” and “Not A” at the same time.