Back then, it was easy to form a coalition because the guilty party (and his party) was clear, so the other party could make political hay by pursuing an invest

Back then, it was easy to form a coalition because the guilty party (and his party) was clear, so the other party could make political hay by pursuing an investigation. In this case, both (major) parties have a lot of blood on their hands. There's no meaningful coalition in Congress that stands to win from such an investigation.