Former US president Donald Trump escaped a second assassination attempt during a golf outing in Palm Beach, Florida, on Sunday after the Secret Service spotted a gunman hiding on the perimeter of the course. Agents quickly moved the Republican presidential nominee to safety after opening fire on the gunman, who was some 400 metres away from Trump.

The incident, which followed a shooting in July, has led to heightened scrutiny of the security measures in place for Trump, with President Joe Biden saying the Secret Service needs “more personnel” to bolster its capabilities.

Acting Secret Service Director Ronald Rowe sought to reassure the public, affirming that the current protective measures are “working”. He noted that the suspect did not have a clear line of sight on Trump and fled the scene before shots could be fired. Although the golf outing was not on Trump’s official schedule and his security detail had to improvise, Rowe emphasised that the security plan had "worked out" in the end.

The shooter, identified as 58-year-old Ryan Wesley Routh, reportedly lay in wait on the course with an AK-47-type rifle for almost 12 hours.

Read moreWhat we know about the latest apparent assassination attempt on Donald Trump

Even before Sunday’s incident, the July 13 attack – in which Trump was shot in the ear but not seriously hurt at a Pennsylvania rally – had raised questions about the Secret Service’s ability to protect the former president.

Kimberly Cheatle, the agency’s director at the time, resigned 10 days later, acknowledging her share of responsibility for what she described as “the most significant operational failure of the Secret Service in decades”.

To address any security shortcomings, the Pentagon stepped in in late August, providing additional military support for Trump’s protection through the 2024 presidential election and potentially until the inauguration in January 2025.

“A second serious incident, apparently involving an assault weapon, is deeply alarming and appalling,” said Senator Richard Blumenthal, chair of the Senate subcommittee investigating the July incident, to the The New York Times.

Palm Beach County Sheriff Ric Bradshaw admitted that the level of security around Trump’s golf course is limited.

"At this level that he is at right now, he’s not the sitting president – if he was, we would have had this entire golf course surrounded,” Bradshaw told a press conference on Sunday.

Michael Matranga, a former Secret Service agent, called for Trump to be given security equal to that of a sitting president, given the attempts on Trump’s life. "The incidents are unprecedented," Matranga told The New York Times.

Trump, on the other hand, seemed rather satisfied with his protective detail. He took to Truth Social to thank the Secret Service for their efforts, writing in all caps, "THE JOB DONE WAS ABSOLUTELY OUTSTANDING."

Read moreTrump back on the campaign trail after weekend assassination attempt

Golf course challenge

The Florida golf course where Trump was playing presents significant security challenges, given that it is an open-air site surrounded by three busy roads and has multiple access points but few places to take cover.

Trump's habit of riding in his own golf cart, with no special security features or bulletproof glass, adds to the risk.

Former FBI agents have highlighted the difficulty of protecting individuals in such public spaces, especially in open-carry states where firearms are prevalent.

"The pervasiveness of weapons, particularly in 'open carry' states, combined with the inability for us to fully address mental-health issues, makes it nearly impossible to guarantee the safety of even Secret Service protectees," former FBI assistant director Frank Figliuzzi told Newsweek.

These vulnerabilities have further intensified concerns about Trump’s safety, particularly given his tendency to disregard security protocols.

Trump rarely likes to play it safe. Following the July attack, the Republican candidate stood up almost immediately after being knocked to the ground by Secret Service agents, raising his fist in defiance before being ushered to his armoured vehicle.

According to Jérôme Viala-Gaudefroy, a US politics expert at Sciences Po, Trump “broke every protocol” by not following standard evacuation procedures at the time.

“He’s a difficult personality to protect,” Viala-Gaudefroy said, highlighting Trump's preference for projecting strength over complying with safety measures.

After the July incident, Trump briefly heeded Secret Service advice to avoid outdoor rallies. He resumed them in late August, speaking behind bulletproof glass in North Carolina but later stepping off the stage to hug a supporter.

“Donald Trump wanted to show, once again, that he doesn't comply with constraints,” Viala-Gaudefroy said. "Security measures contradict the political image he wants to portray."