To fall under the 'somewhat negative' category,
Graboyes states that the president "governed badly, had serious personal failings, or both."
John Quincy Adams: A great man who rose to his highest level of incompetence.
Martin Van Buren: A fixer who was not suited to the top role. Helpless against the Panic of 1837 that was the hangover of the Jackson years.
Lyndon Banes Johnson: One of the most skilled and competent presidents ever but his policies have left lasting damage, notably Medicare and Medicaid. No personal ethics. His handling of Vietnam.
Richard Nixon: Competent and skilled, he resolved LBJ's Vietnam disaster and established relations with China. However, he embraced bad economic policies (price controls) and destroyed his presidency by his actions regarding Watergate.
Gerald Ford: Creditable job of post-Watergate leadership. Bad foreign policy and economic policies.
Bill Clinton: Though he had the makings of a somewhat positive president with his political skills, moderated views, charming demeanor, and strong intellect, he poisoned it with his sexual scandals, financial shenanigans, perjury, and unpardonable pardons.
Barack Obama: Ended NASA monopoly on space which allowed SpaceX to flourish, took out bin Laden. His embrace of racial division, frequent attacks on his predecessor, and beneficial treatment of Iran were harmful. He created a cult of personality that his party has yet to overcome.
Donald Trump: Despite a long list of impressive accomplishments (Abraham Accords, Jerusalem embassy, smashing ISIS, energy independence, end of the Iran Deal, the COVID vaccine, roaring economy, low unemployment - notably for blacks and Hispanics, border enforcement, Space Force, and Judicial appointments), Trump more than offset it with his verbal diarrhea and J6 catastrophe.
Joe Biden: He reversed most of the positives of the Trump administration. The end of energy independence once again filled the coffers of adversaries: Russia & Iran. Iran financed Hamas (October 7 attack in Israel and the latest Gaza War), Hezbollah, and the Houthis (Red Sea conflict). Inflation. Open border, mobs at homes of the Supreme Court, obvious signs of dementia.
Mostly, I'll agree. He's a bit hard on Martin Van Buren. He had some foreign policy successes that determined the borders of the United States and Canada, but that Panic of 1837 really sank him. The Amistad was just a footnote. Nixon established the imperial presidency, seeking to create executive positions that duplicated the Cabinet in order to expand those protected by executive privilege. Given how many positives he lists for Trump, the negatives must really weigh a lot in his estimation.