My guess is that they used Northam to test the Overton Window on how far they could ultimately push the coming abortion laws they absolutely need, like when they had Griffon do the Trump-head photo immediately after his election to test how palatable the idea of killing him was to the public. If the public seemed indifferent, keep pushing further; if they reacted badly (as happened, especially after the NY law was so openly celebrated) get rid of him and quickly install his replacement who's literally the same thing in black-face. Either way all these new late-term abortion laws mean RBG is either already dead or sitting in the grave waiting for the end to come. They want state-laws in place so if/when anything happens to Roe v Wade in Trump's Supreme Court they can fall back on individual state laws to keep the blood flowing instead of having a blanket federal approval.
They're erroneously implying it wasn't a Democrat this time as well