It was just over two months ago that the United States was shocked and appalled by an attempt on Donald Trump's life at a campaign rally in Pennsylvania.

The Secret Service faced intense and immediate scrutiny over the failures that allowed a 20-year-old gunman to climb onto a nearby roof and fire at the former president, grazing his ear and killing one of his supporters in the crowd.

Congressional inquiries have since been opened up, security has been boosted, and the former head of the agency has stepped down.

Today's incident did not take place during a campaign stop. Trump was playing golf, at his own course, not far from his Mar-a-Lago residence.

But as a former president, and current candidate, he receives around-the-clock protection.

The agent who'd gone up ahead of him and spotted the suspect's weapon acted quickly, according to authorities.

Trump and those he was with were not harmed, and his team has praised the actions of those on the ground.

But it raises a fresh set of questions about the level of security he's being provided with.

"You got to understand, the golf course is surrounded by shrubbery. So when somebody gets into the shrubbery, they're pretty much out of sight," local sheriff Ric Bradshaw told a media conference.

"And 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. But because he's not, security is limited to the areas that the Secret Service deems possible."

The Secret Service's acting head, Ronald Rowe, has previously said he was "ashamed" of what happened in Pennsylvania. He's reportedly now on his way to Florida as his agency deals with another suspected attempt on Trump's life.