How Trump's assassination attempt compares to the attempt on Ronald Reagan's life in 1981

The assassination attempt made against Donald Trump during his campaign rally in Pennsylvania over the weekend sent shockwaves through the nation and added the former president to a list of American leaders who have been targeted by gun violence.

The shooting Saturday left one spectator and the suspected gunman dead, two others injured and Trump bleeding from a gunshot wound to his upper right ear.

In the days following the attack, many have been left to wonder how the harrowing event will impact the remainder of the election season -- a question history books may offer insight into.

The attack on Trump garnered immediate comparisons to the attempt on the life of then-President Ronald Reagan in 1981.

On March 30, 1981, gunfire erupted outside the Hilton Hotel in Washington, D.C., as Reagan was exiting the building after delivering a speech before members of the American Federation of Labor and Congress of Industrial Organizations.

The shooter, John Hinckley Jr., fired six rounds from a .22-caliber revolver at the president, who had his hand raised, waving to the crowd. The bullet hit Reagan's ribcage, just inches from his heart, and punctured his lung.

Three other individuals were also shot in the attack, including Reagan's press secretary, James Brady, who was disabled from the gunshot striking his head.

As shots rang out, the then-70-year-old president was immediately swarmed by Secret Service agents and pushed into a waiting limousine that rushed him to George Washington University Hospital for life-saving emergency surgery.

The striking visual similarities between Reagan and Trump being swarmed by Secret Service agents during the attack and both men having a raised hand at the time of the incident (Reagan before and Trump with his fist in the air after) -- are noticeable.

Both presidents also sought to display an image of courage and resilience in the aftermath of the shootings. Reagan chose to walk into the hospital despite being seriously wounded; Trump opted to make his scheduled appearance and speech at the Republican National Convention only two days after the attack.

Another resemblance between the two attacks is the scrutiny surrounding the Secret Service. Hinckley Jr. was able to shoot at Reagan as he was exiting the hotel because he positioned himself among a crowd of journalists and spectators who were not screened by security ahead of time, according to the Associated Press.

At the rally in Butler, Pennsylvania, the building where suspected gunman Thomas Crooks scrambled onto the roof and opened fire was the staging area for the local police tactical team watching the crowd, two law enforcement officials told ABC News.

Sources previously told ABC News that the building had been swept, but investigators are trying to determine whether roof access had been properly locked down.

While the political landscape has changed since 1981, only time will tell if the attack on Trump will garner the lasting admiration and public approval felt by Reagan, whose already high approval rating only increased after the shooting, according to a Gallup poll.

Additionally, Reagan's "Make America Great Again" campaign slogan, famously co-opted by Trump in the 2020 election and throughout the 2024 election cycle, is another political tie that unites the two Republican leaders.

According to the Congressional Research Service, direct assassination attempts against presidents and candidates have occurred on at least 15 separate occasions.

The four U.S. presidents who were assassinated were Abraham Lincoln, James A. Garfield, William McKinley and John F. Kennedy.