"They’re not interested in debate. They’re interested in undermining you and preventing you from writing more. They’re there because conservatives have this methodology called ‘owning the libs.’"

There is no established equivalent to this on the left because there is no longer a "left" in politics. Even the think tanks and political action groups normally associated with left leaning politicians are actually well to the right of Eisenhower, and perhaps even Reagan. We have not had true left leaning leadership since Johnson, and even his governance was questionable in its motivation.