You can already tell that the Trump administration will get away with whatever it wants
Yeah sure. That's why there's no special counsel investigating it. That's why there isn't a grand jury convened to investigate Flynn. That's why Manafort isn't under criminal investigation by both the Feds and NY.
Your assumption that there is no political costs to this story continually running is erroneous. How long can the Senate not do
this?
Republican leaders can hold out only so long in the face of 39% approval ratings, double digit Democratic leads in the Congressional ballot, and a President finding it very hard to move his agenda because of the constant bombshells by the two major institutions (CIA & FBI) that dog him. You're pretending there's this vast majority of silent voters who will continually reward Republicans with victories nonstop and brush this under the bush.
Our democracy amazingly works pretty well in the face of presidential malfeasance and judging when a scandal will be damaging enough or not.