It’s easy to explain.
Hillary and her husband commit various crimes in pursuit of money, power and higher office. As a fellow Democrat, Obama can’t afford for her to squander her chance as it will reveal flaws in his administration.
Obama decides to unleash his administration to investigate Hillary’s challenger — Donald Trump. Through misuse of law and power, the investigation is launched.
Trump detects the vile intrusions. He announces it and a complicate media belittles his claims to shield the lying Obama administration. To prolong the effort they forward elaborate Russian contact and misdeeds to try and undue the Obama victory.
Reasons for the present leak:
1. A good guy in the Deep State
2. The Deep State knows something big is about to break against them and are trying to cushion the fall.
As someone already pointed out, if they had something, it would have already been put out.