This definitely extends beyond kids shows, as a conversation, but Copaganda is EVERYWHERE. Almost every show is a police procedural nowadays, and it’s always like “Cops are the good guys, whether they’re getting criminals, supernatural monsters, aliens, or whatever. They’re here to protect us.” It also exists in games, like the Resident Evil franchise is built around (early on in the franchise) that “The Police are here to investigate the evil pharmaceutical company turning everyone into Zombies.” The first 3 games largely feature cops, even though they find out the system is “corrupted” it plays into that whole “Well, they’re the good cops, and it’s these people on the Umbrella payroll who are the bad guys.”
There’s also the sibling of Copaganda, military propaganda with cartoons like G.I.Joe and the such where it’s just like “The military is here to protect us against the evil terrorists trying to blow up the moon.” (I’ve never actually watched G.I.Joe besides the funny dubbed after-episode special messages, but I assume that’s what happens in the show.)
Maybe I’m just rambling in these comments, apologies for that. I guess what I’m mostly saying is that all of these things sort of all play into it and a cultural brainwashing of society to “always trust cops”, even when there’s things that portray cops poorly, there’s always that lone “Jim Gordon” type that is there to hammer home the “Not All Cops/Few Bad Seeds” message.