Sure, happy to weigh in. There is no sound basis for Alan Dershowitz to claim that abuse of power is not an impeachable offense. In addition to being at odds with common sense, this claim is contradicted by a clear and consistent body of historical evidence. /1
Some of the best evidence comes from the case of Warren Hastings, which informed the drafting Art. II, Sec 4. The fact that he was not guilty of treason, but still deserved to be impeached, was a major reason “other high crimes and misdemeanors” was added to the Constitution. /2
Edmund Burke drew up impeachment charges against Hastings in 1786, and his trial began in the House of Lords in February 1788. Burke’s celebrated speeches and reports against Hastings—widely reprinted in US newspapers at the time—often accused him of abuse of power. /3
E.g., in a trial speech on 2/15/1788, Burke said: “It is by this tribunal, that statesmen, who abuse their power, are accused by statesmen, and tried by statesmen; not upon the niceties of a narrow jurisprudence, but upon the enlarged and solid principles of state morality…” /4
“...It is here that those who by the abuse of power have violated the spirit of law can never hope for protection from any of its forms; it is here that those who have refused to conform themselves to its perfections can never hope to escape through any of its defects…” /5
The next day (Feb. 16, 1788), Burke charged that Hastings “took advantage of the imperfections of the institution [i.e., the East India Company] to let in his abuse of the powers, with which he was intrusted.” /6
Finally, in an April 1794 report, Burke wrote that the House of Commons had chosen to impeach Hastings “because the inferior courts were habituated...to try men for the abuse only of their individual and natural powers, which can extend but a little way.” Burke then added… /7
“...But in the cause which your managers have in charge, the circumstances are the very reverse….The abuses, stated in our impeachment, are not those of mere individual, natural faculties, but the abuses of civil and political authority.” /8
There are many other sources & precedents that undercut Dershowitz’s claim. For example, abuse of power was one of the articles of impeachment adopted by the House Judiciary Committee against Richard Nixon in 1974 and against Bill Clinton in 1998. /9
In the impeachment of President Andrew Johnson, House Manager Benjamin F. Butler of Massachusetts defined “high crime or misdemeanor” to include “the abuse of discretionary power from improper motives or for any improper purpose.” /10
At the 1787 constitutional convention, Edmund Randolph explained that “The propriety of impeachments was a favorite principle with him [because]… The Executive will have great opportunit[ie]s of abusing his power.” /11
Finally, there is the text of the Constitution itself, which imposes solemn obligations of “faithful execution” on the President in exercising all of his executive powers. Abusing delegated powers is the antithesis of faithfully executing them. /12
All of these sources and others like them (e.g., Hamilton’s remark on the “abuse or violation of some public trust” in Federalist 65) suggest that Dershowitz - and Trump - will have a hard time making a persuasive case that “abuse of power” is not an impeachable offense. /13
For at least some GOP Senators, Republican voters, or others who profess to be originalists, however, Burke’s impeachment of Hastings may be the most relevant and instructive precedent confirming what should be obvious: grave abuses of power can be impeachable. /14
