When discussing the media in the area of American government, what is the word for an event that involves familiar people, has a sensational element (conflict, scandal, etc.), is timely, and has potentially high impact?
I believe the term that you are looking for is salient. When I tracked down a practice quiz from the unit you're working on, it was the term that made the most sense. Salient is generally defined as very important or noticeable, which would meet the description in your question.
One of the approaches you could use to explain why events like this are salient could include a psychological approach. Psychologically, we are driven to engage with the things around us that are familiar because it is a safer interaction due to prior knowledge on the subject. This is called the mere-exposure effect. We can analyze and account for factors when dealing with familiar subjects. This is why articles about familiar or well known people are more interesting in general to us, because we are programmed to interact better with familiarity.
Psychology also gives a good reason for why its important that the article have a sensational element. Much of human self-image comes from the concept of comparable self-worth. In other words, "I make 4 million dollars a year, that's great! Oh, he makes 5 million, now I don't feel so good." Because these sensational media representations are often negative portrayals of the individuals involved, it allows us to feel better about ourselves because, comparatively, we look pretty good.
We are also more likely to pay attention to current or recent events as they have a higher chance of directly or indirectly affecting us, which is why it is important that the event be timely. This applies as well to it being high impact. The higher the impact, the better chance we can personally be impacted.
I'd say a "hot topic," "front page news," or "headline news."