You are absolutely correct.
The Slimes is her biggest cheer leader.
Apparently, some powerful Demoncrats talked to them and gave them their marching orders.
"Kill the Hillary nomination."
They are acting like 'good Soviets' and complying.
I assume the illustration is from the time of the Bolshevik seizure of power or the period just before that—the banner in black with white letters reads “All power to the soviets!” (meaning the councils that had been set up, like in 1905—the word had not yet acquired the overtones it had later).