The first few days of rolling out my new book, Faithless Execution, have been exhilarating, with few things more gratifying and humbling than the wonderful review by one of my very favorites, PJ Media’s own Roger Simon.

It has been uplifting to see how many people really are alarmed—rather than indifferent, as I worried—to the problem of rampant presidential lawlessness. People really do grasp that the separation of powers, which is so threatened by President Obama’s usurpation of the powers of the states and other federal departments, really is the key to protecting our liberties. Too much accumulation of power in one government official’s hand—particularly, the Framers observed, the joining of the legislative and executive power in a single department or person—is the road to tyranny.

When people grasp that, they similarly grasp that presidential lawlessness is not a conservative versus liberal issue, nor Republican versus Democrat. It is a question of whether we still aspire to be a republic under the rule of law instead of subjects under presidential whim. If they are not knocked down, the precedents that President Obama is setting for imperial executive power will be available for exploitation by every future president, regardless or party or ideological orientation. That ought to frighten all Americans, not just opponents of the current president’s policies.

I make a sustained attempt in the book to explain that impeachment—the ultimate constitutional response to presidential lawlessness—is a political remedy, not a legal one. You can have a thousand impeachable offenses, but if there is not a strong public will that the president be removed, impeachment is a nonstarter. The political case for removal is the one that is uphill. Establishing the legal case for impeachment—i.e., demonstrating that high crimes and misdemeanors have been committed—is the easy part.

That is because “high crimes and misdemeanors,” a term of art the Framers borrowed from British law, does not refer to penal statutes defining what we commonly think of as crimes and misdemeanors. They are, as Hamilton put it, the “political wrongs of public men”—breaches of fiduciary duty by high officials in whom great public trust is reposed. The concept is much more resonant of the military code of justice than penal laws, embracing such offenses as dereliction of duty (such as a commander-in-chief who replenishes Taliban enemy forces in wartime) and the violation of an oath (such as the oath to preserve the Constitution and faithfully execute the laws).

On that score, former Attorney General Michael Mukasey gave a great explanation of impeachable offenses in an interview on Fox News Sunday with Chris Wallace. I wish I had thought of it myself. Judge Mukasey pointed out that the Constitution gives presidents an unreviewable, absolute pardon power. Thus, he explained, if the president suddenly decided to pardon, or commute to time-served the sentences of, every single convicted prisoner in federal custody, he would have violated no law in doing so. He would, however, be guilty of a massive abuse of power—what the Framers would have called maladministration on a shocking scale. He would not have committed a crime; but he would surely have committed a high crime and misdemeanor.

As it happens and as I argue in Faithless Execution, President Obama violates—and unilaterally amends, and selectively enforces, and purports to “waive,” and ignores—many federal laws. But his real offenses are dereliction of duty, the violation of his oath, and his comprehensive attack on our constitutional framework. It may be unlikely that the public will for his removal from power will ever be strong enough to command the votes of 67 United States senators. But it is essential to the future of our republic—if we are to remain a republic of laws, not men—that we recreate the political conditions in which there is a steep price to be paid for presidential lawlessness. That is my modest goal.