If you think American colleges are Liberal you have never been in a Montessori classroom or known a Montessori teacher. You have to remember that Montessori is FRENCH!
They promote a Free Will Education for children. Okay kid, you do not want to do math? No problem. Do some Art or sing a song. Run around the room if you like. Perhaps after lunch we can go to a save the Whales Rally or even a pro abortion protest.
Maria Montessori was Italian.
My boys each went to Montessori preschool and Kindergarten. The classes were small and they were taught by Catholic nuns (order of St Francis.)
By the time they were four, they could read, write, do simple math and picked up after themselves without being told. It was a wonderful experience for our children.