Dear Senate Majority Leader Mitch McConnell and Speaker Paul Ryan,

I know you are not in the habit of reading open letters from liberal columnists. But I hope you will make an exception in this case since I am trying to avoid partisan talking points and predictable arguments.

Donald Trump is probably the weakest president America has had since the 1920s. Yes, I know that sounds odd since the president dominates every news cycle with his provocative tweets and his explosive comments. But little of that has anything to do with governing.

Consider the three core functions of the modern presidency — presiding over foreign policy, managing the federal government and providing legislative leadership. Trump, as I am sure you will privately admit, fails on all three dimensions.

The only reason the United States has the remnants of a coherent foreign policy is because of the three generals who try to constrain the president: John Kelly as chief of staff, H.R. McMaster as national security adviser and James Mattis at the Pentagon.

Disinterested in anything beyond the Oval Office (except for rallies), Trump is neither an adroit manager of the federal government in the style of Dwight Eisenhower nor an inspirational leader in the model of Ronald Reagan.

And as you both know from the health care fight (sorry to bring up Graham-Cassidy) and the debt ceiling negotiations (sorry to bring up Chuck Schumer and Nancy Pelosi), the president invariably sows chaos on Capitol Hill rather than corrals votes.

Do you really believe the president will be an effective salesman for tax reform? More likely Trump will mangle the details, make promises on tax rates that you can’t deliver and then offer self-defeating ultimatums on the timing of the votes.

Beneath Trump’s bluster, no one is home at the White House. There is an obvious constitutional remedy to fill this dangerous void — Congress should reassert powers that it let lapse during the era of strong presidential leadership.

The imperial presidency was largely a creation of Democrats from Franklin Roosevelt to Lyndon Johnson. Congress playing its original role as a true co-equal branch of government is an inherently conservative notion.

North Korea and Puerto Rico offer two illustrations of how Congress might act in bipartisan fashion in areas normally reserved for the White House.

“A declaration of war”

Over the weekend — in a bellicose tweet that alarmed foreign policy specialists in both parties — Trump warned that if North Korea continued its nuclear threats, “they won’t be around much longer!”

Just heard Foreign Minister of North Korea speak at U.N. If he echoes thoughts of Little Rocket Man, they won’t be around much longer!

— Donald J. Trump (@realDonaldTrump) September 24, 2017

North Korean Foreign Minister Ri Yong Ho responded at the United Nations by saying through an interpreter, “Given the fact that this came from someone who holds the seat of the U.S. presidency, this is clearly a declaration of war.”

This might have been a moment for the congressional leadership in both parties to issue a statement pointing out that under our system of government, it is Congress alone that has the power to declare war. And they might add that barring an attack on Guam or our allies, America has no intention of waging war.

In normal times, it might cause problems for Congress to muddy the message from the president. But these are not normal times. The Washington Post reported Tuesday that North Korea is trying to arrange meetings with GOP security analysts “to make sense of President Trump and his confusing messages to Kim Jong Un’s regime.”

For the most part, the North Korean issue has been left to a few legislators who care about foreign policy. Tennessee’s Bob Corker, who chairs the Senate Foreign Relations Committee but announced Tuesday he won’t seek re-election, recently expressed confidence after private meetings that the Trump administration has a coherent plan to deal with North Korea.

Well, maybe.

But all this depends on the generals reining in Trump’s explosive instincts. That’s why — to prevent America from blundering into a nuclear conflict — Congress should hold a series of high-profile hearings to clarify our government’s policy toward North Korea.

No guarantees

When it comes to Puerto Rico, everyone in Washington is finally, albeit belatedly, moving in a compassionate direction. The president has pledged to go to Puerto Rico next week. And you, Speaker Ryan, have rightly called this “a humanitarian crisis” and promised Puerto Ricans “that they’re going to get the kind of help and aid that Texas and Florida enjoyed.”

If this were a typical administration, that would be enough. But given the mercurial nature of the president’s attention span, there is no guarantee federal assistance will be distributed with the urgency required. As a result, Congress should aggressively monitor the relief efforts in Puerto Rico rather than assume its legislative responsibilities begin and end with appropriating funds.

Please understand, Leader McConnell and Speaker Ryan, that none of this requires you to publicly denounce Trump. We all can read polls and know that nearly 80 percent of the GOP base supports the president. We also know poll numbers for both of you are, to put it politely, not nearly as robust.

But that does not mean you should automatically defer to Trump because he is nominally a Republican. Loyalty in Trump World is a one-way street. In Alabama on Monday night, Steve Bannon, who could easily return to the Trump inner circle, said about you, Senator McConnell, “Your day of reckoning is coming.”

As congressional leaders, both of you have a choice of how you will be remembered during this time of reckoning. There is honor in being remembered for upholding the constitutional powers of Congress in the face of a reckless and unsteady president.

Roll Call columnist Walter Shapiro is a veteran of Politics Daily, USA Today, Time, Newsweek and The Washington Post. Follow him on Twitter @MrWalterShapiro.