The verdict on Trump is in, but the jury is still out on Biden and the election

After decades of carefully skirting lawlessness in his business, political and "romantic" affairs, Donald Trump has finally been held to account by the US legal system. Mr Trump was found guilty in the adult film star hush money case in Manhattan, making him the first former president to be an adjudicated felon. But the impact on the 2024 election is unclear.

Mr Trump was condemned by a jury of his peers in the city that knows him best. He was strikingly convicted on all 34 counts after only two days of deliberations. It’s a decisive legal defeat, though each of his other three pending criminal cases – the purloined top-secret documents case in Florida, and the federal and Georgia state prosecutions over his alleged efforts to overturn the 2020 election – are far more serious both legally and politically.

It is still possible that the federal anti-democracy plot case could go to trial before the election, but the Supreme Court is dragging its feet on a simple and unnecessary ruling upholding a lower appellate court finding that, obviously, former presidents are not immune from criminal prosecutions.

Both the Trump campaign and that of his presumptive opponent, US President Joe Biden, issued statements agreeing that the historic conviction won't have much impact on the campaign or the election. Both have vowed to continue as planned. But, although both sides are likely to indeed persist with their existing strategies, the guilty verdict in fact could have a huge impact on the outcome.

Mr Trump's team and supporters are breathlessly insisting the convictions actually help his chances in November. They point to a potential fundraising surge, just as occurred when he was indicted in Georgia. That could well happen, and one of his key fundraising websites crashed immediately after the verdict, possibly because, as the campaign claims, it was overwhelmed by small dollar donations from his base.

Yet this is almost certainly empty bluster. His core supporters won't care that he is now a convicted felon, as well as an adjudicated sexual abuser, defamer, fraudster and tax cheat, as determined by other recent civil cases. And they would have the same reaction to convictions in any of the other cases. The same applies to the disgraceful response by most elected Republicans who have rallied to his defence and condemned the process as "entirely political" and utterly illegitimate. There is nothing, apparently, whatsoever, that would shake the dedication of his party to its dear leader.

But the fact that the core of the Republican Party has become something of a personality cult does not mean that the relatively small number of uncommitted voters in swing states share this bizarre blind allegiance. They may well find this conviction, and the despicable reaction of Trump and other leading Republicans in attacking the US judicial system to be the last straw.

Mr Biden is unpopular. And many Americans insist that the country is in an economic recession when, in fact, it is economically robust and they report that their own finances are doing well. Many also believe that unemployment is at a 50-year high rather than the actual 50-year low. Some of this is because of relatively high inflation and interest rates, meaning that the cost of borrowing and keeping money is high. But it is also the result of persistent and shameless propaganda by right wing media that have pushed narratives about crime and economic rates that have been highly misleading, to put it charitably.

But Mr Trump appears to be even more unpopular, and that will only be exacerbated by these criminal convictions. Mr Trump's reaction, lashing out not merely at the prosecutors but at the jury, the judge and the legal system as a whole, is characterised by the kind of unpatriotic and, let’s face it, downright anti-American outbursts that won't help him with the swing voters he must win over.

Because both men are distinctly unpopular and are effectively both incumbents running for second presidential terms, the election probably boils down to a simple formula. If it is a referendum on the president, as a re-election campaign normally would be, Mr Biden is likely to lose. But, if it is instead a referendum on Mr Trump, then it is the former president who has chance of prevailing. The criminal convictions as well as earlier devastating civil judgments only underscore that reality.

Mr Biden's campaign will not only focus on making the case about his own presidency and plans for the next four years. It will goad and provoke Mr Trump, and sit back and watch him expertly make the case against himself. Age, his party's seemingly endless adoration and the recent pseudo-monarchical trappings of the presidency have all combined to increase his arrogance, raging narcissism and shocking inability at self-control.

Unless Mr Trump's rhetoric and personal behaviour suddenly moderate, his potential for creeping self-destruction as the campaign moves along is enormous. And his own fixation on himself, his endless grievances and his antipathy for all existing American institutions, now focused on the judicial system as a whole, may make it impossible for him to shift the focus onto Mr Biden.

The candidates have agreed to two debates, but it was always questionable whether Mr Trump would ultimately show up for them. That potential evasion is now even more plausible, since Mr Biden could and certainly should hammer on the point that only one of the two candidates on the stage is a convicted felon, as well as an adjudicated sexual abuser and fraudster.

Mr Trump still retains a huge amount of public support and has been leading by small margins in most polls of swing states. Polling data in the next few weeks, as the impact of the criminal convictions is measured, will be very significant.

But the campaigns are both right that this probably will not be determinative. Neither side has yet found a key breakthrough moment that creates decisive momentum and forms a winning coalition.

But the bottom line is that Mr Trump's conviction cannot possibly be a positive for him in winning back the presidency. It is, at the very least, a serious blow. And while, on its own, it may not guarantee Mr Biden another term, it could well be a key part of an overall message about Mr Trump's fitness for office that ultimately secures victory for the Democrat.