WASHINGTON, D.C. — The return on stocks since Donald Trump’s presidential election win in 2016 has slumped to 24% thanks to the historic rout the past three weeks, undercutting what had been a better-than-average gain for American leaders over the past half century.

That leaves him on course for the worst performance since George W. Bush’s second term, by the metric of total return on the S&P 500 Index. Equity investors saw more than double the returns under Jimmy Carter, who battled stagflation and foreign-policy crises in the late 1970s.

The lack of inflation nowadays means that in real terms, Trump still comes out ahead of Carter, who lost his re-election bid to Ronald Reagan. But by any measure he’s now well behind the 63% climb in Barack Obama’s second term. That Obama mark is slightly less than the total return for Trump when Wall Street hit a record high on Feb. 19.

Equities may still rebound by Election Day on Nov. 3 and many strategists, at least before Thursday’s crash on Wall Street, were predicting a recovery once the coronavirus peaks, potentially in the second quarter. But the sudden collapse in shares underlines the communications challenge for Trump, who had repeatedly touted the gains since his election as a key achievement for his administration.

To-be-sure, no other modern U.S. leader has faced an event quite like a global health pandemic. Its spread is causing an unprecedented shock to economies all over the world as policy makers grapple with ways to shield their populations from the deadly virus.

The S&P 500 crashed into a bear market on Thursday after Trump’s Oval Office address the evening before failed to spur confidence that the administration will avert the first recession since the global financial crisis. Trump stopped short of a broad-brush fiscal package.

And his assurance that “no nation is more prepared” for the coronavirus conflicted with the assessment the next day from the leading U.S. infectious-disease official that America’s testing system is failing.

“The longer the social-distancing without offsetting stimulus continues, the lower the odds of Trump winning the election will go,” Evercore ISI strategists including Dennis DeBusschere wrote in a note Thursday.