A great quote, from someone you wouldn’t expect.  Your guesses in the comments.

Competition is like water held in a sieve.  To argue that competition does not exist
because it is absent somewhere is like saying water is not leaking because one
of the holes of the sieve is plugged.
Thus the burden of proof in the competitive-versus-noncompetitive debate
is on those who would argue lack of competition.  The proponents of the noncompetitive view
have demonstrated that only a few of these holes in the competitive sieve are
plugged.

Please don’t Google-and-guess!

Update: The answer, as Don Boudreaux correctly guessed, is my honorable nemesis Donald Wittman.  It’s not surprising, of course, that Wittman would claim that democracy is competitive.  What’s surprising is that he makes a general claim about competition which, if true, undermines a wide range of democracies’ efforts to “increase market competition.”