When were there two presidential assassination attempts this close?

The news that Donald Trumpfaced a second apparent assassination attempt over the weekend, this time at one of his Florida golf clubs, was a shock to the system.

The encounter, where Ryan Wesley Routh allegedly stood within 500 yards of Trump holding a military-style assault rifle, came just 64 days after Trump was in the crosshairs in Pennsylvania, where a gunman came within inches of potentially killing the former president, grazing his ear with a bullet.

Assassins have killed four U.S. presidents— Abraham Lincoln, James Garfield, William McKinley and John F. Kennedy—part of 18 total plots against presidents and presidential candidates. However, one Republican president faced two assassination attempts in even shorter succession than Trump.

In 1975, Gerald Ford faced two attempts to kill him in the span of just 17 days.

The first came on September 5 in Sacramento, where Ford was in town to meet California governor Jerry Brown.

Gerald Ford survived two assassination attempts (1974 AP)
Gerald Ford survived two assassination attempts (1974 AP)

As he left his hotel room and greeted a crowd, a woman in a red dress pulled out a gun.

"The assassin was tried and convicted, and her name was Lynette ‘Squeaky’ Fromme, and she was a member of the Charles Manson family," supervisory curator of the Gerald R. Ford. Library and Museum, Dr. Mirelle Luecke, told CBS Detroit in July.

Then, on September 22, another would-be assassin, Sara Jane Moore, tried to attack Ford on his way to an AFL-CIO convention in California.

The plots eventually inspired Ford to wear a bulletproof trench coat reinforced with Kevlar, Dr Luecke told CBS.

Donald Trump is helped to his feet following the first assassination attempt against him (AFP via Getty Images)
Donald Trump is helped to his feet following the first assassination attempt against him (AFP via Getty Images)

"Ford talked about, you know, he understood it was really important to wear this vest, and he felt really obligated to do so, but he disliked wearing it because it was hot and heavy; it weighed over six pounds," she added.

The plots against Trump may inspire changes of their own.

Both incidents raise the question of why someone armed with a high-powered weapon was able to get within striking distance of a former president, who still retains a Secret Service detail.

The Pennsylvania incident – on July 13, when the former president was shot in the ear by a gunman who was killed by Secret Service agents – prompted Kimberly Cheatle, head of the Secret Service, to resign, and an internal Secret Service probe has reportedly revealed multiple lapses in planning and communication around the Butler shooting.

Lawmakers say they’ll hold a public hearing about the incident later this month.

Sen. Richard Blumenthal (D-Conn.), said last week that lawmakers "will have a report very, very soon that I think will absolutely shock the American people about the lapses and lags in protection that was afforded that day and the breakdown in communication, failure and responsibility.”