This is a brilliant tactic, and I've been trying to persuade conservative leaders to adopt it ever since seeing your original post.
Democrats can only win national elections now by capturing 75%+ of the black vote. Without it, they are toast. At the same time, they have to stake a claim to a tiny sliver of the white vote and as big a share of the growing hispanic vote as possible. It's a fragile coalition in the best of circumstances.
By forcing them to choose now (before the typical Gramscian dialectic process has "mainstreamed" reparations), we have an opportunity to split that coalition for good and deal a serious blow to the contagion of identity politics.
Most white Democrat politicans simply won't be able to support reparations...yet. It's too fringe, too alientating, and too unAmerican. But by going on the record against reparations, they alienate their black base. On the other hand, if they do come out in support of reparations, they will lose even more ground with whites and hispanics.
This issue could be as explosive and damaging for the Democrats as European integration has been for British Conservatives.
Keep up the pressure!
This is why I said before that reparations are actually a gift to Republicans. There is no way that we could concoct a means of destroying the Left like this. Dems are putting themselves in the proverbial knight-fork with this issue (for those who don't play chess, a knight-fork is when your knight is safe from attack from your opponent's pieces, yet still has at least two of your opponents pieces in jeopardy: in other words, no matter which move is made, you will take at least one of your opponent's pieces).
No matter what, we should not allow them to sit back and allow this issue to ever become mainstream because if it does, say goodbye U. S. of A.
I hope that they are listening. . .