I don’t know about CA, but Federal law for Federal offices like House, Senate and President makes a clear distinction.
It is illegal to pay a non-citizen, and illegal for a non-citizen to receive pay, to do anything political.
Volunteer work is totally different. Consider, non-citizen Christopher was paid by Clinton/DNC to do oppo research. Clearly illegal. Mexican former President Fox to in effect campaign for Clinton and against Trump. Both very political. But as far as I know, Fox was a volunteer. Totally different.
So were the Dreamers paid?
DOJ Whittaker went in like a lion and came out a lamb.