What’s weird about this is I think you are right, rioting almost always drives the electorate rightward.
A better tactic for Obama would be to tell these people to chill, then to send Eric Holder on a witch hunt to find a couple of Wall Street Banker types they can perp walk before the election. Abuse Executive power to force banks to drop their debit card fees, freeze foreclosures, and start taking steps to put usury caps back on credit card interest. All that would rebound much more to Obama’s political benefit than a riot.
So....why is he doing it?
Riots in every major city will drastically decrease economic activity.