If the random reader encountered the book in a bookstore, I suppose I’d most want them to glance through one (or all) of three chapters:Chapter Four describes the Framers’ deliberations over the constitution and its impeachment clauses, and thus sets the framework for everything that follows.Chapter Seven treats the impeachment of Andrew Johnson and advances one of the most important (and probably controversial) arguments in the book. I contend that impeachment is not merely a tool for expelling criminal, grossly incompetent, or corrupt officials, and is indeed not even limited to evicting presidents who threaten existing constitutional norms. Rather, I argue impeachment plays a role in those rare situations where the country is at a constitutional crossroads – a point in history where a fundamental choice about the country’s future must be made – and the president and Congress have an irreconcilable disagreement. I conclude that, “In the impeachment clauses, the constitution confers on Congress the power, in the last extremity, to choose its fundamental vision of America over the idiosyncratic view entertained by the individual person occupying the presidency.”Finally, I’d recommend Chapter Ten, which summarizes the lessons of history and frames final chapters’ discussion of the situation presented by Mr. Trump.In my role as constitutional historian, I have striven for political objectivity. Nonetheless, the lessons history teaches compel what will undoubtedly seem to some a partisan conclusion. Put simply, impeachment is the Constitution's defense against a president who, by conscious design or because of defects in his character, threatens republican government. The Framers made impeachment hard because they didn't want Congress throwing out presidents in partisan hissy fits. Still, the framers meant it to be used if, somehow, a manifestly unfit person were to become president and endanger the constitutional order they so carefully constructed. Donald Trump is the contingency for which they gave us the weapon of impeachment. The question is whether our politics is so broken that we lack the will even to pick it up.