To understand how politicians misuse a graph like this, you have to understand about vandals vs builders and time. Otherwise you’re just setting yourself up for the con.
You have a house. You will live in the house for one week, and Joe will live it for one week.
Joe is a party animal. During his week he wrecks the place and causes all kinds of problems with neighbors, complaints, broken walls, wrecked furniture, broken windows, etc. When it’s your turn you have a week’s worth of fixing up to do, and while you’re doing it, people are coming to the door to talk to you about the parties that happened last week, and cops are charging you for those parties, and so on. When Joe comes back the house is great, as is the yard. Cops drop by to tell Joe the place looks great, and neighbors give him a thumbs up. After a couple of days he starts having parties again, and by the end of the week everything is anarchy. You arrive just in time to get all the complaints from cops, neighbors etc., and set about fixing everything. By the end of the week you finish, just in time for Joe to arrive, and so on.
A report is written up about the two of you. A graph is made. It shows that when you are in the house it is broken down, the garden is ruined, there is rubbish everywhere and the cops receive complaints from angry neighbors. By contrast, when Joe is there the house is clean, perfect, no complaints and the cops reckon he’s great.
The graph proves it.