It's an issue because over the decades he's been involved in public life he's always fielded claims he's a racist. Whether it's the policies he's advocating or the campaign he runs or the friends he keeps. However one could always make a case that this was circumstantial and taken out of context. Indeed he often did at the time.
Now there's growing first hand accounts of him being a racist prick that are harder to shake off. So that's the turning point.
Sadly I don't think any of this will matter. Racists will flock to him regardless of these stories. My only hope is that he sucks the racist elements out of Labour and the Tories leaving them to both be more compassionate welcoming parties. Note: this has backfired somewhat and they're both trying to out racist the Farage 🫠.
We're doomed.