Voter suppression is well documented. Here is a conversation about it that is easy to understand.
https://www.vox.com/2019/1/24/18186741/voter-suppression-gerrymandering-carol-anderson
Here is a survey of methods. https://www.americanprogress.org/issues/democracy/reports/2018/11/20/461296/voter-suppression-2018-midterm-elections/
What I don't see evidence of is what the meme claims that Democrats are telling people how to vote. Of course they are advocating that you vote for them, that is what politicians do.
In my opinion if Republicans were serious about courting the Black vote they would make it easier of eligible people to vote. The intended effect of these anonymous memes, is propaganda, is to create outrage, so that even if a small number of people stay away from the polls, it will have worked.