How can you agree that "the press may not be successful much of the time in telling people what to think" and at the same time think we're easily manipulated?

Because the bar for manipulation is not “think X”. It’s very possible to move public opinion by the way things are worded, presented, and brought up without ever going as far as saying “think X”.

Heck, very very few advertising campaigns involve telling the user to buy a product or service. Most focus more on creating a new need/want, or in repeated exposure to make the advertised good seem “normal”.

Now the tricky thing is that manipulation requires intent, which is very hard to prove. Hanlon’s razor would have us believing that in most cases, shady things happen because people are dumb, not malicious. So for my part I personally believe that the media got addicted to the ratings and felt internal pressure to provide equal coverage even when the scandals were quite unequal.