Americans have increasingly soured on the Secret Service following the assassination attempt in July that wounded former president Donald Trump, according to a Gallup opinion poll released Monday.

The poll shows that Americans who rate the agency tasked with protecting presidential candidates and government officials as good or excellent tumbled 23 percentage points, while the share of those rating the Secret Service’s performance as poor rose by the same margin.

The findings were published amid intense scrutiny by lawmakers and government investigators over the agency’s failure to prevent a gunman who climbed atop a roof and fired at Trump during a campaign rally in Butler, Pa., grazing his ear, injuring two others and killing a rallygoer.

The polling was conducted almost entirely before the Secret Service thwarted a potential attempt on the former president’s life on Sept. 15, this one at the Trump International Golf Club in Palm Beach County. In that case, a Secret Service agent spotted an armed man on the club’s perimeter and opened fire. No one was injured and the suspect was taken into custody.

According to Gallup, the poll stands in sharp contrast with many of previous ones during the past decade asking Americans to rate the performances of federal agencies. The Secret Service has typically enjoyed a broad positive rating from the public, although support slipped in 2014 after several security lapses, including an intruder breaching a White House fence.

It’s the largest such decline for a federal agency in the reoccurring poll since the Centers for Disease Control and Prevention’s favorability ratings dropped by 24 percentage points between 2019 and 2021 during the height of the coronavirus pandemic.

Only the U.S. Postal Service enjoys positive ratings among U.S. adults, according to Gallup. Support is equally dim for other agencies including the Justice Department, the Food and Drug Administration and the Internal Revenue Service: less than 35 percent of Americans rate their performances as good or excellent.

The Gallup poll found that the Secret Service’s positive ratings have dropped steeply among Republicans and independents who lean toward the GOP: 20 percentage points since last year, their lowest rating to date. Favorability ratings from Democrats and Democratic-leaning independents also fell by 18 percentage points from 2023.

Pollsters interviewed 1,007 randomly selected adults in all 50 states and the District of Columbia from Sept. 3 to Sept. 15; Gallup calculated the margin of error as plus or minus four percentage points.

A Secret Service internal review released last week found that the agency was to blame for a series of lapses leading up to the July 13 shooting, including the failure to direct local police snipers to cover the rooftop and detect the gunman flying a drone in the area hours before the shooting.

The Department of Homeland Security, which oversees the agency, is negotiating with Congress to dramatically increase the agency’s budget and expand personnel and upgrade equipment. Acting Secret Service director Ronald L. Rowe Jr. is urging elected leaders to boost funding so the agency can deal with its “new reality.”

A bipartisan House task force investigating the Pennsylvania shooting is scheduled to hold its first hearing Thursday.

On Sunday, a task force leader, Rep. Jason Crow (D-Colo.), said the Secret Service is “no doubt stretched thin.”

“We are in a threat environment where threats are at historic highs,” Crow said on ABC’s “This Week.” “We’re asking the Secret Service to protect a sitting president and then two presidential candidates and then former presidents and all their families in an environment where threats are three times, four times higher.”