On that basis, any charge against Trump could be classed as interfering with an election. Which is patently nonsensical. 'Hey, I'm standing for office' is really not much of a defence. And the fact that he is likely to be nominated as the Republican nominee is not, and I'll repeat most definitely not, a cause for a mistrial. The appeal has to be based on matters relating to the conduct of the trial itself.
As has been very well explained by
@A2SG the jury were given three routes to the actual charge. Only one needed to be accepted beyond reasonable doubt to lead to the charge itself. The fact that there were three doesn't reduce the need for certainty by a third. It literally doesn't matter that any of the jurors could have been convinced by any or all of those three. The prosecutors would have been exceptionally careful in ensuring that the routes they gave to the guilty verdict were valid. And there is absolutely no doubt that the judge would have weighed his instructions to the jury
very carefully indeed.
This wasn't some slapdash, run of the mill suck-it-and-see shot in the dark by some junior legal eagle from the prosecutor's office overseen by some judge who wasn't really paying attention. This was a case against a former president. The care that went into ensuring the processes were absolutely watertight would have been greater than probably any case that either the prosecutors or the judge had been involved with.
It really is wishful thinking to hope that there'd been some mistakes made that will give cause for a genuine appeal. But hey, nothing is set in stone. It could happen. But try getting any Trump supporter to give a verdict on the judicial system as regards the appeal before it's actually decided. The system is only broken if it's rejected. It's only fine and dandy if he gets off.
I doubt you'll find anyone who thinks that Trump doesn't deserve to be considered for president who doesn't say that the result of the appeal will be accepted. But you'll have a hard time finding any MAGA supporters who will say the same. Doesn't that give you pause for thought?