Senate could impeach Trump or other members of the administration, but that requires a two third majority so good luck with that. Note that impeachment is specifically excluded from the presidential pardon.

But other than that, yeah, the strategy seems to be "who is going to stop us?" It remains to be seen how far he can push things because a critical majority of Republican senators will balk. For all their talk about "muh constitution" over the last few decades, they sure seem quick to abandon some basics when it's convenient. And even then it remains to be seen if he actually steps down after an impeachment conviction.