George HW Bush was no one’s idea of a great president. His 1988 presidential campaign was the first I followed as a child in the US – supporting, under my mother’s instruction, his hapless rival, Michael Dukakis – and even then he seemed strangely unquantifiable, a blank. His presidency bore this impression out, in which his credit sheet was cancelled out by enough debit that the balance ultimately came to nothing.

A war hero and famously polite, Bush Sr signed the Clean Air Act and the Americans With Disabilities Act (protecting, among others, people with HIV, from discrimination), and eventually spoke out against the National Rifle Association. But he was also arrogant, careless and self-serving. He exploited racial politics and pardoned the defendants in the Iran-Contra hearings to protect himself from investigation.

He kowtowed to America’s evangelical right, and under his watch, Aids ravaged the US more than any other developed country. He left a mess in the Middle East and his vice-presidential choice of Dan Quayle – a pro-life hawk who famously couldn’t spell – set the Republican party on a course that eventually led to Sarah Palin and Donald Trump.

After Bush’s death was announced last weekend, the predictable schism opened in the reactions between two extremes: on the one side, the cap-doffing hagiographies, and on the other, a hipster-esque “burn the elders down” condemnation. And yet the anecdotes about the now late president that seemed to tickle people the most, even some of the cynics online, were ones about his relative lack of partisanship.

References to Bush’s support for Hillary Clinton were reverently repeated on the news, as was his unlikely friendship with Barack Obama. Most of all, his gracious letter to the then-incoming president Bill Clinton, welcoming him to the White House after losing his bid for re-election against him, pinged ecstatically across the internet. Ah, for the days when politicians could put aside their political differences for the good of the country, went the collective sigh across half my social media feed. And across the other half, something very different was going on.

At the same moment people were cooing over Bush’s letter, Kate Osamor, the shadow international development secretary, announced she was resigning from the Labour frontbench after it was reported that she had misled the public. Previously the Labour party had said Osamor was unaware of the legal case against her 29-year-old son, Ishmael, who was caught with £2,500 worth of drugs at Bestival last year and charged with intent to supply. This, it was originally claimed, was why she continued to employ him as her chief of staff.

In fact Osamor had written to the judge asking for leniency and, given that her son was caught with a haul of 250 ecstasy pills, plus cocaine, ketamine and cannabis, but was not given a custodial sentence, her request was arguably granted (the judge mentioned the strong letters of support, as well as accepting that Osamor had been looking after the drugs for friends. His – judging from the amount of drugs – many, many friends). When asked about this by a reporter last week, who went to Osamor’s home for a response, she reportedly replied, “I should have come down here with a bat and smashed your face in” and threw a bucket of water after him.

Osamor has now resigned, and quite right, too. But it was genuinely dispiriting to see so many on the left vehemently defend her, using frankly spurious arguments about the futility of drug laws, the hypocrisy of journalists moralising about drugs when many of them take them, and the media’s racial bias. All those points are surely true but irrelevant in this circumstance, given that Osamor resigned following allegations that she lied to the public, not because her son was caught with drugs.

If journalists really cannot see the immorality in defending a politician who has abused another journalist, just because the politician is a member of the party you support, it’s hard to know where to go from here. After all, even Fox News supported CNN’s Jim Acosta when the Trump administration went after him. This kind of blatant partisanship is as common on the right as on the left, as the Trump fanatics and die-hard Tories prove, and it’s hard to fathom how anyone thinks this simplistic nonsense helps – or fools – anyone. It’s perfectly possible to support a politician and still have criticisms; or, inversely, not to support them but also acknowledge their strengths. Otherwise, you’re just a propagandist.

George HW Bush, of all people, knew that, which is why he went against his own by-then-rabidly partisan party to support Hillary Clinton. Many others, on the left and the right, don’t, and it’s doing the political climate no favours. As a result, everyone else looks back sentimentally to the days when Bush – now, amazingly, a comparative titan of commonsense – was in charge. We need to be better than this.