Julian Zelizer is a history and public affairs professor at Princeton University and the author of " The Fierce Urgency of Now: Lyndon Johnson, Congress, and the Battle for the Great Society ." He's also the co-host of the " Politics & Polls " podcast. The opinions expressed in this commentary are his own.

(CNN) Recent news stories about the Trump White House and the fears voiced by prominent legislators like Senator Bob Corker raise a serious question: Is it time to consider the unthinkable and look at the options offered by the 25th Amendment?

While this kind of discussion seemed premature a few months ago, there is mounting concern that the President could spiral out of control and, if this is the case, with his finger on the nuclear arsenal, be a danger to the Republic.

There have now been a number of troubling pieces of information to emerge about what is happening behind closed doors. Senator Corker, the chairman of the Foreign Relations Committee, said in no uncertain terms that a handful of advisers such as Secretaries James Mattis and Rex Tillerson are the only people that "separate our country from chaos." In his subsequent interview with the New York Times, Corker went even further by saying that, "I know for a fact that every single day at the White House, it's a situation of trying to contain him" and that his public statements could put the United States on a path "towards World War III."

Numerous stories in the media have confirmed the impressions of Senator Corker. Writing for Vanity Fair, Gabriel Sherman recounted his conversations with several White House advisers and prominent Republicans, all of whom described a White House where the people around the President spend almost all of their day trying to contain his erratic behavior and dark mood swings.

Sherman reports that, according to one former official, Chief of Staff Kelly and Secretary of Defense Mattis even discussed what to do if the President attempted to launch a nuclear war.

Politico published a story based on interviews with current and former administration advisers, recounting how most of their time is spent managing the President and trying to make sure he doesn't act on some of the plans he barks out after watching television. And then of course there was the NBC story, which President Trump predictably dismisses as "fake news," about Secretary Tillerson referring to the President as a "moron" after a meeting in which Trump floated the idea of a massive increase in the nation's nuclear arsenal.

As if all of this weren't dangerous enough, there is the unsettling behavior that the nation has seen right before its own eyes. The manner in which President Trump has handled the escalating crisis with North Korea, including the kind of name-calling tweets one might expect to find on a child's smartphone, his reactionary comments about the white supremacists in Charlottesville, his making light of police brutality, the relentless attacks and direct threats on the news media, and the heartless comments that he made about Puerto Ricans as they are still recovering from a massive natural disaster, don't do much to reassure us that this is a president fully in control.

Even if this is some kind of well-orchestrated public relations strategy meant to "distract" or "appeal to the base," it doesn't make things much better. The notion that a president would rationally choose this path suggests a leader who cannot be fully trusted to use the power of the presidency within reasonable bounds.

If all this is true, and Republicans like Corker stand by their statements, then we are entering into unprecedented territory. We come closer to accelerating a serious conversation that the nation's leaders will need to have about whether to trigger the 25th Amendment. The Amendment offers a mechanism to remove a president who is incapable of fulfilling official duties.

Ratified in 1967, the 25th Amendment aimed to establish clarity about the presidential succession of power in the aftermath of the tragic assassination of President Kennedy four years earlier. Since the Constitution did not fully elaborate on how a vice president became president when there was a death, a resignation, or when the commander in chief was unable to perform his or her duties in office. Section I of the Amendment stipulated that if a president vacated office because of death, resignation or having been removed, then the vice president would take over. Section 2 enabled the president to name a new vice president with the approval of Congress should that office be empty.

The key part of the Amendment that is relevant today has to do with a process for handling a situation where the President can't perform his official duties. Though the drafters had physical disability in mind, with President Trump the conversation has shifted to mental competency.

According to the Amendment, the vice president and a majority of the "principal officers of the executive officers" could recommend that a president be removed from office if they believe that he or she is "unable to discharge the powers and duties of his office." Once they send this declaration to Congress, the vice president becomes the "Acting President."

The president would then have the right to respond by proclaiming, in writing, to Congress that he could perform his duties. Upon doing so, he would resume his power unless the vice president and the majority of the cabinet within four days send another declaration to Congress. The House and Senate then would have 21 days to make a final decision. A two-thirds majority would be necessary to confirm a transfer of power.

As would be expected, this is an incredibly convoluted and, by design, difficult process, and there are many points at which it could be halted. There is also considerable ambiguity in the language of the Amendment to challenge the circumstances under which it can be used (meaning to address the psychological rather than physical condition of a president).

And this is how it should be. Regardless of how much some voters might hate President Trump and despise everything that he stands for, removing a president from power is an action that should be taken only under the most urgent of circumstances and where there is no other alternative.

We must as a nation to do everything possible to respect the democratic will as it is expressed on election day. As this conversation continues, politicians and citizens must remember this at each step. If the reality is simply that we just have a weak and untalented president, and one who pushes for ideas that many voters reject, then this conversation should come to an abrupt end and voters can make a decision about what to do in the next elections.

Follow CNN Opinion Join us on Twitter and Facebook

Using the 25th Amendment based on psychological or mental grounds is in many ways an even bigger step than impeachment, given that this would be a dramatic action overturning the election based on criteria that would be difficult to determine with any kind of certainty. The measure can't be used because officials don't like who a president is or don't agree with what he is doing. The bar must be much, much higher.

Better than the 25th Amendment would be for the regular mechanisms of politics -- such as tougher congressional oversight or more effective electoral pressure on legislators to push back against the president -- be the means through which Trump is restrained.

But if the evidence continues to mount that our democracy has a president who is psychologically unfit to handle the duties of office, and thus too dangerous to be trusted with so much power, then those who are standing in the inner sanctum of power and witnessing this firsthand need to take action.

Tweeting, leaking, grandstanding, and writing op-eds are not enough. If the President is really a threat to the Republic and to the world, then Vice President Pence and a sizable number of cabinet officials like Secretary Tillerson have a duty to let their conscience move them to protect the nation, rather than stand idly by, merely hoping for the best.