A monument suggests Trump was an aberration, but marginalized people know he is a more openly expressed continuation of violence inflicted on them since the country’s founding. Because this violence predates Trump and will likely outlast him, it cannot be commemorated as past. It is not past tense.
For the record, I do actually think that public art commemorating the evil that happened during the Trump administration is necessary and good. That is part of how we build a national conversation and prevent this from ever happening again.