Has Trump been instrumental in creating a climate of incivility that exposes racism and bigotry always here amongst us?

He didn't create the fire but he damn sure fanned the flames.

He lit the underbrush that allowed the conflagration.  When people see their president being uncivil and speaking disrespectfully to so many people, they think it's permission for them to do the same.  After all, if the president can do it, why can't I?

No

Creating it, no - it's been around since before the Civil War. What Trump has done is encourage it, allow it to flourish and refuse point blank to condemn it.

     Trump creates division instead of 
a bringing together.
He is without a doubt IMO
a white nationalist building walls
of division 
instead of bridges of unification.
He has Alt Right members in his cabinet
that need to be fired.
He refuses to stand against the white supremacists 
that brought him to power and to denounce them.
....so he reinforces it as has been said.

sounds like it

Don't forget Trump's father was arrested at a Klan rally for violence, and charged for not letting properties to black people. I don't think he is somehow divorced from the racialists who support him. They recognise him as fully one of their own.