About Constitution being rewritten, what are you referring to?
rewritten in an indirect sense - just ignored and re-interpreted as seen fit, which is de-facto re-writing it, only much, much easier of a process.
Off the top of my head, you can think of the republicans denying Obama the appointment of a Supreme Court judge in his last year of service.
More recently you have Trump influencing with a tweet the guilty verdict vs one of his hench-man, Roger Stone - that was a clear violation of the separation of power, which is one of the most foundational principles in the Constitution.
Then you have the refusal by republican senate to allow witnesses as part of the impeachment proceedings, which came after complete disregard for subpoenas issues to people in the administration.
That's really just the tip of the iceberg. So many of the things that have happened over the past 3-4 years had never happened before, be it during republican or democratic administrations.