This is all about turning the "Russia collusion" witch hunt on its head to try to expose the fact that the Clintons were the ones actually colluding with Russia, China, North Korea, and others. In effect they are taking this media shitshow and making it risky for them to keep pushing it because the whole reason it began was to draw attention away from their own crimes. Accusing your political opponent of what you have been doing is a classic political tactic that automatically makes them seem petty and refractory initially regardless of how much truth there is to it. Sessions is refusing to act on these matters, and the Democrats are pushing the justification for this so it is much easier for the Republicans to justify their own special council as a result.