Hi Brock!

Thanks for your question!

I’m afraid it won’t be possible to put cards into different categories during the voting session because the Voting feature mostly allows leaving votes on particular board objects rather than sorting these items.

As a workaround, I’d recommend using Sticky notes of different colours (each colour representing a particular group) or coloured dots from the Dot Voting template to divide your cards into categories. 

Alternatively, feel free to use this Card Sorting template from our Template Library to organise a a card sorting session. 

Hope it helps!