The impeachment system is obviously defective as William Jefferson Clinton has proved.
He was never in any “jeopardy of life or limb” whatsoever. At most he could have lost his job.
This is a difficult issue. On the one hand, I don’t think that Trump should be prosecuted for the documents. It not a crime, or at least not the kind of offense that should be prosecuted. But I don’t see how you can exempt a president from any crime, including murder, committed while he was in office. The SC might have to draw a line somewhere.