If you fear a Donald Trump presidency you are now left knowing that the last line of defence to prevent that outcome is someone even more vulnerable to attack than previously thought. For months Hillary Clinton’s team has denied claims from opponents that she is suffering health problems.

In New York today, the Democrat candidate was taken unwell at the 9/11 ceremony and rushed away to her daughter’s apartment. After an hour her team admitted that she had got “overheated”. That seems to be spindoctor talk for sunstroke or fainting. ‎What was behind it? What is really wrong? What happened in that missing hour? Can we hear from a doctor? Is the truth being told? Parts of the US media will now ask such – legitimate – questions from now until polling day in November. The health of the potential leader of the US is an entirely fair subject for examination in an election campaign.

For Donald Trump – the implausible poltroon and ego-maniac menace – this presents a great opportunity at a point when his campaign was already reviving. He can cite her health problems and widen his attack to suggest that she simply cannot be trusted on the basics. Attention will also shift to Tim Kaine, her running mate who looks about as presidential as Stan Laurel.

The Democrats – and those others abroad who don’t want Trump in the White House – may be about to pay a high price for backing a truly terrible candidate, someone who has been in the public eye far too long (inducing annoyance and boredom) who has been embroiled in too many scandals and misjudgements that taint her reputation. She is struggling in the spotlight, and as her remarks last week about Trump voters (“a basket of deplorables”) show, she has no instinct for turns of phrase or for reaching out beyond her tribe. The Democrats would have been much better off with someone old and trusted (a Biden) or someone fresh. That was Obama’s insight in 2008, that the Clinton story in terms of the presidency was done, that voters had had enough. Obama was right and he won. The dynastic Clintons could never accept that, which meant they came back for another go. They should not have done it.