Aside from the typical election game shenanigans (tons of parties, naked expies of both real people and fictional characters from pop culture, blatant self-inserts, etc.), that's a lot of presidents who died in office.
Post-POD, you guys have killed off twice as many presidents (13- Crittenden, de Clinton, Dewey, Blaine, Muller, Bonaparte, Fitzgerald, Hoover, Orléans, Jones, Bell, Potter, Murillo) than died in office IOTL (6- Lincoln, Garfield, McKinley, Harding, F. Roosevelt, Kennedy) in a similar period of time.
For further reference, I thought I'd explain how each President who died in office met their demise:
Crittenden- "A small cabal of Confederate sympathizers started a plot to assassinate President Crittenden. On October 15, 1862, they attacked his carriage while he was traveling, shooting him twice and killing him."
de Clinton- "Soon after taking office, President de Clinton became the fourth president in a row to be the target of an assassination attempt. He was shot, but narrowly survived. The assassin claimed to be a New England secessionist trying to save the Union from the Confederate tyranny of de Clinton. In a highly publicized trial, he was eventually found not guilty by reason of insanity. This ruling became even more controversial when, on June 17, 1878, President Nathaniel Jay de Clinton died after a period of sickness. It remains disputed whether the wounds he received in the assassination attempt contributed to his death."
Dewey- "Dewey suffers a major heart attack in office. While it initially seems as if he might recover, the president dies on February 14, 1890."
Blaine/Muller- Alexander J. de Clinton, son of the late President de Clinton, defeats Blaine in the 1892 Conservative convention when the President tries to run for a full term. In response, Blaine recreates the Democratic Party and runs as its nominee, and in a huge upset defeats both de Clinton and the Democratic-Republican candidate. Alexander doesn't take this all too well, and "de Clinton shoots and kills President Blaine during a town hall meeting held shortly after his inauguration on March 10th, 1893. The President survives through the first few bullets, but the last bullet is fatal and goes straight through his heart's veins and arteries. The President is declared dead on the scene. One of the bullets hit VP Muller, piercing his jugular vein and leaving him heavily bleeding on the ground. The blood loss is too rapid for doctors at the scene of the assassination to handle, and they declare the impromptu President dead just hours after Blaine is pronounced dead."
Bonaparte- "On November 3, 1903, President Henry Napoleon Bonaparte was shot by a self-proclaimed anarchist. He became briefly comatose and died a week after the incident."
Fitzgerald- "President Fitzgerald apparently could not handle the stress of his second term. He died after a stroke on November 15, 1921."
Hoover- Hoover was able to lead the country out of the Gatling Depression, but lost World War II, which cost him the election against Orleans and the Conservative candidate. In response, he ordered FBI Director Huey Long to have Orleans killed. Meanwhile, Hoover would try to dissolve Congress, and seize power as a dictator. However, Long decided to take Hoover on a drive into the Maryland countryside, and after the driver, who was in cahoots, handed him a pistol, "he suddenly slammed Hoover's head to the front seat and fired two rounds through the skull, then opened the door and kicked the body out to lay in the bushes nearby." A week later, the President's dead body was discovered, and the FBI revealed his plans to start a self-coup(with any evidence of their involvement wiped, of course). To this day, no one knows who the assassin was.
Orleans- "A few hours ago, Orleans decided to visit one of the poorer neighborhoods in Boston. Empathize with the commoners, stuff like that, give him some political bonus points. To not make it awkward for the locals, he decided to travel there only with light protection, a few guards, that's all. And what do you know - one of the local unemployed in the streets stole a pistol from somewhere and took a few shots at the President. He's been detained - name's John Kennedy, a number of diagnosed medical problems, unfit for service and decided to lay off his anger of the Commander-in-Chief - but the President is gravely injured."
Jones- "On December 23rd, 1966 in the midst of speaking to a crowd of college graduates at Indiana University in Bloomington, Indiana, an assassin shoots and kills President Jones during his speech and upon being tackled by the crowd, it's quickly discovered that the assassin is also a suicide bomber and the bomb in his chest detonates once he hits the ground, killing dozens of college graduates and gravely injuring both the President and Vice President. The assassin and suicide bomber is discovered to be Huey P. Newton, a radical black nationalist and a member of the SCLA who deeply hated President Jones for what he perceived to be his ambivalence on civil rights.
Both President Jones and Vice President Bell die within days of receiving their critical injuries, leaving Secretary of State Maxie Short as the next President of the United States by January of 1967."
Potter- Potter starts WWIII against communist Germany, who is TTL's version of the Soviet Union, in order to stop Generalplan Ost, a genocide being carried out in Eastern Europe. Unfortunately, Potter miscalculates when he tries to end the war quickly by overthrowing German leader Erich Mielke, and in response, Mielke starts a nuclear exchange that kills hundreds of millions across the globe. "In response to the widespread destruction brought by the nuclear strikes, disgraced former FBI Director B.O.B. Lennon[who had been fired by Potter earlier due to a scandal where the FBI spied on Potter's political opponents that had nearly gotten Potter himself impeached] decided to follow American tradition by orchestrating an assassination plot against President Potter. He would personally shoot the president while a bomb would dispose of as many cabinet officials as possible. Lennon, who sought to include as many people harmed by Potter's actions as possible, risked discovery due to the size of the plot, but the skilled spymaster remained undetected by the distracted federal government. The plot went into motion on April 20, 1984. The bomb was detected as soon as it entered D.C., triggering alarms throughout the city's security system. However, there was not enough time to save the president, who was shot by Lennon twice and died a few hours afterwards."
Murillo- In response to the Radical Murillo being elected, Louisiana Governor Jim Buckley announces the formation of the National Salvation Government, a far-right organization that wanted to overthrow Murillo and restore decades of conservative dominance. The government began treating the NSG as terrorists and in response, "Buckley took the actions of a terrorist and concocted a plot to kill President Murillo, Vice President Moon, and Secretary of State Bonaparte. The scheme went into action on May 1, 1987, May Day. National Salvation soldiers shot the President and Secretary of State; the former died hours later, while the later was initially expected to survive before his death on May 4. However, Vice President Moon was not at the scene and the terrorist sent to assassinate her was caught by security."