If the impeachment inquiry against President Trump moves to a trial in the Senate, Sen. Cory Booker (D-N.J.) told reporters this week, his role there must take precedence over his presidential campaign. "We are doing something that is with the gravity of removing the sitting president from office," Booker said. "I will be there. I will be focused. And I will do my work."

Insofar as any member of Congress deserves plaudits for promising to prioritize duly representing his constituents over seeking greater personal power, that's dandy. But Booker's framing of his work as remedying a crisis of presidential misconduct evinces a too-common misconstruction — and one which helped us into this mess in the first place. It makes the legislature's restraint on executive power entirely ex post facto, letting lawmakers skip the more necessary work of trimming the imperial presidency back to its basic administrative roots.

Impeachment is necessary and sometimes unavoidable, but it is not prophylactic. Partisanship keeps it from functioning as a reliable protection against future wrongdoing, because even the worst presidents can expect near-lockstep support from their own party in Congress, and almost every president in the last half century has had at least a few years of a friendly majority in one house or both.

Divided government likewise offers no guarantee of accountability, as House Majority Leader Nancy Pelosi's foot-dragging on this very impeachment inquiry has revealed. Political considerations, chiefly alienating independent and swing voters, will often outweigh ethical concerns. "High crimes and misdemeanors" are significantly in the eye of the beholder, and the beholder is looking at the next election cycle.

That reality makes impeaching the president rather like a trip to the emergency room. Yes, it might save your life. It's also mostly unconnected to the day-to-day of responsible, healthy living — except if it's your own fault that you're in the emergency room, in which case the visit should prompt some changes to whatever part of your lifestyle is the culprit.

The congressional Democrats spearheading this impeachment have no apparent intention of making such a change. They'll bandage a broken skull and send the patient right back to biking without a helmet. They'll try to oust this president and leave the very same tools of corruption and abuse for the next one. They'll let him claim, in deed if not in word, that he has the "right to do whatever he wants as president," armed with pen and phone.

This state of affairs can only be acceptable to the selfish or naive. It appeals to politicians and partisans because the power they persistently leave unchecked will sometimes fall to them. Why melt the crown if it may yet rest upon your head? And it appeals to those who retain a civics class credulity about American politics, clutching against all evidence to the belief that we may yet develop markedly better and broader electoral tastes. Unless Mr. Rogers rises from the grave with a hankering for the campaign trail, I wouldn't count on it.

The safer and more certain option is massive structural reform. Congress must put meaningful restrictions on the power of the presidency. The executive branch has for decades crept beyond its proper administrative function to usurp congressional authority, dictating the priorities of state well beyond the vague leeway of executive discretion.

Incidentally, it is this very pseudo-lawmaking which made Trump's alleged quid pro quo possible. Reform could indicate to foreign leaders that the president is an administrator with no power to refrain from disbursing funds Congress told him to disburse. It could place stricter limits on national emergency declarations, ensuring the president cannot unilaterally move money around in direct contravention of Congress. It could significantly curtail presidential immunity, making the president subject to indictment. Perhaps most importantly, it could limit the scope of executive orders, the favored method for presidents of both parties to exercise unconstitutional policy-setting authority.

This is a difficult and unlikely ask in that it requires sacrificing short-term partisan advantage for a long-term shot at more functional and congenial governance. I get the implausibility here.

Still I recommend it, and will continue to recommend it forever, because impeachment is confusing, uncertain, retroactive, narrowly targeted, and politically fraught. It may censure or remove a bad president, but it does so only in connection to a small selection of provable misdeeds and via a process that will always be subject to accusations of injustice. The best impeachment remains a contributor to political rancor and fails to stop further executive overreach. It's an ounce of cure when we need a pound of prevention.

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