The decline may be due to Trump's policy of deporting immigrants to a notorious Salvadoran prison without offering them due process and in direct violation of a judge’s orders.

In the past few weeks, it's been reported that most of the people Trump has deported to CECOT—where inmates are packed into inhumane and overcrowded cells without mattresses, pillows, or proper nutrition, and with limited access to legal representation—have no criminal record at all.

The poll finds that a plurality of Americans (49 percent) say Trump’s approach to immigration policy has been “too harsh,” compared with the 38 percent who believe it's "about right" and five percent who say it’s been “too soft.”

In another eye-popping finding, 50 percent of Americans believe Kilmar Abrego Garcia—a Maryland man Trump wrongly deported to CECOT—should be returned to the United States, which the Supreme Court has ordered the Trump administration to do. Just 28 percent side with Trump, who said he cannot and will not bring Garcia back.

The Trump administration has accused (without credible evidence) Garcia of being a member of MS-13—but that messaging appears to be failing. According to the poll, just 27 percent of Americans believe Garcia is a member of the gang.

The poll’s results are similar to a Civiqs poll conducted for Daily Kos, which found 51 percent disapprove of Trump’s handling of immigration, while 49 percent approve.

The polling suggests that Democratic lawmakers' condemnation of Trump’s deportations, as well as their efforts to bring Garcia back, have hurt Trump's standing with voters—a sign Democrats should keep up the pressure.

“Approval of Trump’s handling of immigration fell 10 points over the last week,” G. Elliott Morris, the former polling director at the now-defunct news outlet 538, wrote in a post on X. “Obviously the backlash to the [Kilmar Abrego Garcia] case worked, and it would have been a mistake not to talk about this — from both a rights perspective and the POV of moving opinion against POTUS.”

For example, Democratic Sen. Chris Van Hollen of Maryland recently traveled to El Salvador to meet with Garcia, as did a handful of House Democrats, where they highlighted the dangers of deporting people to a foreign prison without due process.

“Donald Trump and his Administration are running a government-funded kidnapping program– illegally arresting, jailing, and deporting innocent people with zero due process. Kilmar Abrego Garcia is Trump’s latest victim,” Democratic Rep. Maxwell Frost of Florida, one of the Democrats who traveled to El Salvador, said in a news release.

While the immigration data from the Economist/YouGov poll is bad for Trump, other data from the survey is even worse for him. A plurality of Americans (42 percent) give Trump’s first 100 days in office a failing grade.

In fact, a plurality or outright majority of nearly every demographic polled gives Trump an “F” grade, including white Americans (38 percent), every age and income demographic, and independents (46 percent). The only groups that this isn’t true for? Republicans, ideological conservatives, and Trump voters.

That’s likely because Trump has a net-negative approval rating on every issue included in the poll: jobs and the economy (-12 percentage points), immigration (-5 points), foreign policy (-14 points), national security (-3 points), education (-12 points), crime (-1 point), criminal justice reform (-6 points), and inflation and prices (-20 points).

It appears it’s just shy of 100 days in office for political gravity to pull Trump back down to earth.