WASHINGTON — It is hard to imagine that any previous president would have thought he could engage in such an audacious act of self-dealing.AdvertisementSue the government he runs, then settle the lawsuit with himself by barring the IRS from auditing his past returns. And as part of that deal, hand over $1.8 billion of taxpayer money to his allies.President Donald Trump has used the federal government to advance his own personal interests and those of his family and allies more expansively and openly than any past occupant of the White House. Any review of history would suggest that it is...