Somewhere in his biography of Benjamin Disraeli, Robert Blake argues that those unenthused by D would use the older spelling "D'Israeli" to play up his Jewish background. (Changing names seems to have been family routine.) George MacDonald Fraser borrows this idea in Flash for Freedom!
But where does Blake say this? The great name question isn't in the index. I was hoping I'd find it somewhere in the vicinity of a reference to Charles Greville (to whom Fraser also points), but no luck. Any other D enthusiasts know what I'm talking about? Or am I remembering a different biography? I don't think so, though.