The left used to have the meme advantage under Obama but things have changed since. In general the American left has been largely unable to fill the massive hole that Obama left behind when he left office. They can't find someone who is charismatic and able to bring together a coalition of moderates and progressives. Now we have a field of less charismatic politicians, many of whom are nobodies but even among the noteworthy candidates they're representative of this or that segment of the left without being able to create that wider coalition that Obama was able to.
The left had a huge start out of the gates during the neocon/evangelicon shit show of the W admin; Jon Stewart and many, many others did great with that material, and IMO memes track with comedy regarding who's "winning" the humor war.
That said, the right's memes during Obama reflected their gross xenophobia too much and wasn't designed for chuckles, but for fear-mongering, unlike the cracks Stewart took at W etc. Obama wasn't clownish, and the right's memes suffered because of that as well.
Currently, the left's policy proposals/points of conversation are losing people's will to progress, and are easily mocked. Trump is clownish, so the left should be finding good material, however they are now reacting to him as the right reacted to Obama, too serious and trying to spread fear, sounding desperate when laughing at Trump.
Also Trump is affable, like W was, and is not as seriously deranged, so he entertains people more instead of mostly terrifying them like W.
I could distill this and come back with a TLDR at some point, just kinda thinking about it at a meta level for the first time honestly.
Thanks
@Kafir-kun for clearing up the status of this "meme team" as unofficial, I had little doubt.