I propose we send groups to every “town hall” meeting of a Democrat legislator plus this crap Obama does, and shout “that’s racist” after EVERY SINGLE STATEMENT THE POLITICIAN MAKES.
Perhaps that’ll drive the point home that they sound completely effing ridiculous.
What you describe is textbook alinsky. In this case, I wouldn't be surprised if candidate moonbeam sent an advance team to coach supporters, or even spot staff in the crowd to spew this at the planned time. As a matter of fact, I'd wager it was scripted.
To your point, for maximum effect, the "group" needs to be scattered throughout the crowd. When one makes a comment the others shout in agreement or add some supporting applause. To an uniformed observer this looks like a group consensus. There’s also a good chance the speaker gets knocked off track and makes either verbal or emotional mistakes that plant doubt in the rest of the crowd.