The kids after doing hours of research knew only what mattered to them personally. They were spectacularly uninterested in background. They were uninterested in anything that didn't agree with what they already believed. If I pushed them, either they became confused because they sort of realized there was stuff they should have taken into account that they didn't like (and that's just unfair) or they parroted my words back to me for the grade.
Confusion was better for their grade.
And in the end, some kids said I was against DACA and others that I was for it; that I was against "Doe versus Wade" or in favor of it; that I was pro-Trump or anti-Trump. Which is how I like it: Whatever your viewpoint, you'd better be able to defend it, and if you can't I'll dismantle your opinion and let it die, bloodied, in front of you. The problems they researched were all difficult. They presented facile, simplistic answers. If that's your universe, it's hard to understand why what you want hasn't already been done, and the only possible conclusion is that everybody else is stupid or evil. This just compounds idiocy with foolishness.
One article some kids examined really just listed facts. "Did the writer have a bias?" The student would say, "It's just facts, numbers. How can it be biased?" So I'd add some facts and numbers that the writer left out. Suddenly the One True Conclusion was murky. And again, the students were confused. "How were we supposed to know that?" "You were told to research the topic, not just read the article. This article was very biased."
Rule 1 of critical thinking is if you don't know the issues, if you don't know the facts, if you don't have the right background, you can't engage in critical thinking. You can be a PhD in history and a master of your field, but do "critical thinking" in science at a high-school level, if that's where you stopped science. You can be a PhD microbiologist and have the critical thinking skills of an 11th grader in history. Ask an art major to think critically about law, and the best you'll get is criticisms. Not really "criticism" in the sense "literary criticism" or "legal criticism", just a lot of complaints.
For a lot of teaching, regurgitating what the students are told is a sign of their students' critical thinking abilities. Parents do the same--the kids echo the parents, who believe their kids are geniuses for their mimicry. By all means have the kids do research. But you have a bunch of kids and you're not going to give them the wonderful attention that's needed to guide them. Or, if you do, it's likely to be as much indoctrination as education.