My advice – pursue the business of the people of the United States and don’t waste your time parrying and counter punching with Trump. You do you.
Set an agenda and pursue it. If it doesn’t pass the Senate or if it does, isn’t signed by the President, don’t sweat it. Remember Newt’s “Contract with America?” Maybe you should propose something similar.
Whatever the case, just keep on. Be faithful, steady, consistent. You’ll win nothing, no dignity, no respect, no results, none by simply investigating and blocking anything Trump wants to do. And worse, you’ll lose legitimacy by simply being obstructionist. Nobody likes that.