That is PragerU’s typical approach to spreading their message - present something that is subject to interpretation as an immutable fact and then build an argument from there.

I think the idea is that if they can get the audience to accept that the foundation of their argument, even if it isn’t true, it becomes much harder to debunk the weaker points that support or reinforce it. The message will subtly sneak into their consciousness even if they would have disagreed with the overall premise initially, because they will walk away thinking that the people who made the video did their due diligence and researched the facts of the issue and wouldn’t lie about something so fundamental. It sows seeds of doubt, makes them question if the left-wing sources of news are reliable arbiters of truth or facts. Repeat it enough times, and it becomes full-on indoctrination.