Regarding the O/P could you not go to the Teacher/Professor, and ask her to have a quiet word with the three people who seem to be constantly holding back the whole class, maybe if some of your other class mates went to her to (not an ambush mind) it would look better?
To really round out the class, you need a random conspiracy theorist. Those make every class fly past quickly, because you spend the entire time wondering - “Did he really just ask if George Bush met the three witches from MacBeth in World War II? And why did he ask that?”
Seriously, I’m with Obsidian Flutterby. Find a buddy to mock the ijits with. Suddenly, the irritation transforms itself into amusement.
It’s even more fun if it’s the TEACHER spouting random conspiracy theories. My daughter had one of them in high school. I went to the principal about it – I mean, it was really funny the crap he was teaching these kids – and he told me the guy was strong in the union and he couldn’t do anything. But my daughter told him off right after taking her final – told him she thought he was a lunatic and his theories were insane, and then we held our breaths waiting to see how he’d grade her for that. He gave her an A. We suspect he did it to shut her up. 
I went to a women’s college and had to take a few classes with radical feminist professors. (Your basic conspiracy theorist types with a specialty.) I would have killed for a sexist pig type to break up the monotony. Ah, well.
Then I took a Philosophy class at a community college to make up a credit. We were studying Socrates and asking what does it mean to be educated. One student looked up the word “educated” in the dictionary and thought he was so smart for getting “the answer”. Another student asked the professor, “I heard that Plato and Socrates was homosexual, is that true?”
There was no hope of shutting up either student.