Good question.
That VP debate was a disaster for Kaine and the Democrat ticket.
There’s no way he helped gain support for Hillary.
On the other hand, I have no doubt that Mike Pence helped solidify support for Trump and the Republican ticket.
In a close election, running mates can help tip the balance, in either direction.
Maybe Kaine helped Hillary carry Virginia, just maybe. Otherwise he was no help at all.
The debate was a complete disaster and I imagine voter fraud (thank you Punk McAuliffe!) helped out in VA.