The shooting Saturday afternoon that Donald Trump survived is the fourth time in U.S. history there has been an assassination attempt on the life of a U.S. presidential candidate.
Only one of these attempts turned into an actual assassination — shortly after midnight on June 5, 1968, when Sen. Robert F. Kennedy, D-N.Y., barely moments after claiming victory in the California Democratic presidential primary, was shot by 22-year-old Palestinian Sirhan Sirhan as he made his way through the kitchen of the Ambassador Hotel in Los Angeles.
Another attempt on the life of a candidate was unsuccessful, but nevertheless had a tragic aftermath. Having emerged triumphant in the Florida primary and other battleground states in the race for the Democratic presidential nomination in 1972, Alabama Gov. George Wallace was shot four times on May 15, 1972 by a miscreant named Arthur Bremer while campaigning in a shopping center in Laurel, Maryland.
Doctors worked overnight administering numerous blood transfusions to save Wallace's life. But one of the bullets struck the Alabamian's spinal cord, and left him unable to walk for the rest of his life.
Although Wallace won the Maryland and Michigan primaries by big margins a week later, his campaign for the presidency was effectively over. He would serve two more non-consecutive terms as governor and died in 1998.
Political pundits and historians have debated what might have been had Kennedy survived the assassination's bullet or Wallace emerged from the hospital still able to walk.
The late presidential chronicler Theodore H. White concluded RFK would have "definitely" won the Democratic nomination had he lived but is uncertain whether he would have won in November. Former ABC News Political Analyst Jeff Greenfield and former Rep. James Rogan, R-Calif., have both written "what if?" books on Kennedy going on to win nomination and election as president.
But noting that outgoing president and vehement RFK enemy Lyndon B. Johnson still controlled the Democratic Party machinery and that most Democratic convention delegates were committed to his vice president Hubert Humphrey, both former Democratic National Chair Lawrence O'Brien and Chapman University (CA) Prof. Luke Nichter said RFK's chances of winning the nomination were almost nil.
Had Wallace walked out of the hospital in 1972, it's almost certain he would have arrived at the Democratic National Convention with more primary wins and many more delegates under his belt.
It is not inconceivable that he and Humphrey — despite their fierce disagreement over civil rights — might have stopped the nomination of leftist Vietnam opponent and South Dakota Sen. George McGovern. And with Wallace remaining a Democrat, populist Democrats in and outside the South might have done the same rather than moving to the Republican Party of Richard Nixon, Ronald Reagan, and Donald Trump.
Columnist and former presidential candidate Pat Buchanan told a YouTube documentary on Wallace that the Alabamian clearly influenced "Nixon and [Vice President Spiro] Agnew, the Reagan movement, the Buchanan movement, the [Ross] Perot movement."
As to what would have happened had Wallace not been crippled by Bremer's bullet, Buchanan said "a slight movement of the bullet [away from Wallace's spinal cord] changed American politics in a big way."
The first attempt on the life of a US presidential candidate was actually against a former president who, like Trump, was attempting a comeback for his old job.
Thwarted by incumbent President William Howard Taft from the Republican nomination for his old job, Theodore Roosevelt was running in 1912 as the candidate of the Progressive Party. In Milwaukee, Wisconsin October 14, 1912, Roosevelt was shot by an unemployed saloon keeper named John Schrank.
As the crowd pounced on the would-be assassin, T.R. called on them not to harm him and then met with Schrank behind closed doors. Looking the assailant in the eye, the former president asked several times "What did you do it for?" When he got no response, Roosevelt left, urging police not to harm Schrank, and then went to deliver his 90-minute address to a spellbound audience.
"Ladies and gentlemen," Roosevelt told his listeners, "I don't know whether you fully understand that I have just been shot, but it takes more than that to kill a Bull Moose. [his nickname for his insurgent party]." He finally consented to go the hospital where doctors concluded it was safer to leave the bullet lodged in his chest than to try to remove it.
Roosevelt, who came in second in the race won by Democrat Woodrow Wilson and ahead of incumbent President Taft, carried the bullet for the rest of his life.
Reports say that aside from the bleeding in his ear, Trump experienced no ill effects from the gunman's bullet. Whether the incident Saturday in Butler County, Pennsylvania has any impact on the coming Republican convention or the fall campaign remains to be seen.