Another quite popular response is that:
we are not ready for Medicare for All, or

questions about exactly how it will all be worked out.

Democrats should be framing the debate and winning elections on progressive terms, not asking what the GOP will support.

are something I won't engage in and that cuts both ways. We have a disagreement on policy and how it should be implemented. I view games like this as intentionally divisive at a time when we need to fine common cause. By setting up an all or nothing crap shoot in which Republicans have no skin in the game, many stand to lose all. Not something to play games with at all.