I don't understand why Trump doesn't say things like "The Obama administration has a history of using the Government to antagonize political opponents and they've even tried to surveil me" instead of "Obama wire tapped Trump tower". The first makes the point in a vague way. The second has key details that are going to be hard to prove. The MSM will focus on that aspect of his tweets.
This is like the "3 million illegal votes" claim, make it specific and outrageous, and everyone gets talking.