Hello Ian2,
This is new to me; but it does seem to mean "expressing the thoughts that Churchill might have expressed", i.e. acting as a channel.
There is a similar meaning for "channeler", in
Merriam-Webster.
I presume the reference is to this comment by Churchill: "It has been said that democracy is the worst form of government except all the others that have been tried."
With luck, another member will know more about it.
All the best,
MrP