One of our daughters has such a driver, and our daughter is very well grounded so I don't worry about such. She comes home and tells us what the bus driver has said, and we talk about it. The students are not swayed by the bus driver's opinions. They tend to believe the same things as their parents. We have not complained about the bus driver because she is adequately transporting our child to and from school. There are liberals everywhere. Our children must learn to cope. I've never considered reporting the bus driver for having a political opinion.
A school bus ride is just not the same without some good stem-cell talk.