it's a relatively trivial matter to use a printer attached to a voting machine to create a paper-trail.
even something like "choose your candidate, get a receipt, verify it yourself, and put it in the box"
the election results would be instantaneous, and the paper trail would still exist for irregularities.
But pretty much all the software suffers from shortcuts one after another, ridden with bugs and backdoors. Someone will most certainly get to exploit the state of affairs before these systems are solid enough for good.
I wonder if there are methods for mixing identities. Bitcoin mixing services have many people put coins into a pool, then outputs balances to new addresses. It isn't a 1:1 comparison at all, but I wonder if there are methods that could be used.
If more than one identity service is used I wonder if the multiple keys could be mixed to create a unique key that only the voter knows.