Since the end of World War II, just three presidents have faced primary challenges when running for re-election. In 1976, Gerald Ford (whose legitimacy was in question on account of never being elected to the office) was forced into a grueling contest with Ronald Reagan, who had just finished two terms as governor of California and had taken his place as the leader of the conservative movement within the Republican Party. Four years later, Jimmy Carter faced a similarly vigorous challenge from Massachusetts Sen. Ted Kennedy, who challenged the incumbent on leadership and ideological grounds. In 1992, George H.W. Bush found himself in a fight with Pat Buchanan, a Republican operative and commentator who ran on a platform of cultural conservatism.

All three presidents won their respective primaries. All three lost in their subsequent general elections. To the extent that there is a pattern, it is simple: Sitting presidents who have to defend themselves from a party rival are presidents who will probably lose their fight to stay in office. And the reason such presidents would even have rivals is because they are weak and exceptionally vulnerable. Ford had the specter of Richard Nixon and the Watergate scandal; Carter’s approval rating plunged to 29 percent by the end of 1979 amid crisis and stagnation; and Bush faced a slowing economy and a rebellion from right-wing conservatives who slammed him for betraying his pledge of “no new taxes.”

This is the key context for news that some prominent Republicans are quietly taking the kinds of steps that clear the way for presidential runs. Sens. Ben Sasse and Tom Cotton, notes the New York Times, have already made trips to Iowa. Ohio Gov. John Kasich is planning several forums on health care policy and may make a trip to New Hampshire. And Vice President Mike Pence has established a political action committee and packed his schedule with political events, speaking at a key GOP event in Iowa and meeting with major Republican donors.

This activity wouldn’t be so remarkable if we were later in Trump’s presidency and it was clear the president was either uninterested in a second term or so marred by scandal and controversy the party was reluctant to re-nominate him. In that case, it would be political malpractice if the vice president weren’t making preparations for an eventual run. But this isn’t the second or third year of the Trump administration—it’s the first 200 days. And because of that fact, this activity is extraordinary. Imagine if in the summer of 2009, Joe Biden were making campaign stops, or Evan Bayh were speaking to Democratic activists in South Carolina while Mark Warner feted Democratic donors in Los Angeles? In that world, we could say without question that Barack Obama was a historically weak president on the path to defeat.

Can we say the same about Trump? The case for yes is in the numbers. No president stays popular for long, but few presidents have reached the depths of unpopularity as quickly—and stayed there as long—as Donald Trump. Trump has hovered at 37 to 38 percent approval for most of the summer, down from 45 percent when he entered office. And a whopping 57 to 58 percent of Americans disapprove of his job performance. The only recent president to hit that low in his first year was Bill Clinton, who entered office in the midst of an economic downturn and whose first months were also marred by scandal and controversy. But his time in the valley of unpopular presidents lasted just a few weeks, compared with two months (and counting) for Trump.

What makes Trump’s low approval especially striking is that it comes at a time of relative stability. There is no recession or economic crisis holding down his numbers, nor is there a large-scale conflict that has negatively captured the public’s attention like the Iraq war in the final years of George W. Bush’s administration. Under these conditions, the president’s approval should be stable; and yet, it is falling with little sign of improvement. Even with a new chief of staff to manage dysfunction in the White House, Trump is still an ignorant president with little interest in the hard work of governing and an obsession with public image that has compromised his ability to avoid scandal or controversy. When faced with an actual crisis, Trump’s approval may go lower. The nadirs of the Nixon administration (24 percent approval in summer 1974) and the second Bush administration (25 percent in the fall of 2008) aren’t out of question.

If this continues, Trump doesn’t just risk his presidency: He risks the Republican majority in Congress and at the state level. If that comes to pass in the midterms, then Trump will have all but invited a challenge from within the Republican Party. And given his preoccupation with “winning,” any kind of challenge would likely blossom into an outright schism.

Of course, this is all speculation. And while this is the period where party actors begin to make choices about their political futures, it’s also true we’re still years away from the next presidential election. Much can happen between now and then to shift the landscape. Trump, for example, could strengthen his hold on his core support—white working-class voters—thus giving him the kind of advantage in states crucial to winning the Electoral College, like Pennsylvania and Ohio, that could withstand low overall approval ratings.

With all of that said, it is worth making this observation: A world where Republicans run against Trump is one in which, at best, the result will be a poisoned chalice. If Trump is weak enough to be unseated, then the Republican Party itself is almost certainly in some kind of free fall torn apart by internal division. And even if Trump survives such a challenge, it will not bode well for the general election.

As figures like Pence begin to prepare for the fallout from Trump’s failures, they should know that even if they win, they’ll still likely lose.