Spoiler warning: it’s because the Democrats use the concept of “acceptable losses.”
Consider the story of Jim and Patrick Moran… and let us not make this a Democratic/Republican thing. Instead, let us go foreign: imagine that a report had come out that the son of an Australian* politician had been caught viciously beating his girlfriend in a drunken rage. The incident was witnessed by police, who made an arrest (getting assaulted themselves in the process); the victim went to the hospital, and allegedly treated for a skull fracture and a broken nose. Now also imagine that the politician HAPPENED to be a senior figure in his political party, and who HAPPENED to belong to a federal-level legislative body that HAPPENS to have direct oversight over the municipality where the attack took place; and that the politician’s son just HAPPENED to be able to plead down from felony assault to regular assault and probation. And, to cap it all off… the victim is in classic fashion sent out to claim that it was all an accident – and then the politician declares the whole thing to be an ‘embarrassing situation.’
If all of this happened on the other side of the world, do you think that there would be anybody credible – on either side of the American political spectrum – who would not agree that the politician needed to be investigated?