A classical theorem of Burnside asserts that if chi is a faithful comp
lex character for the finite group G, then every irreducible character
of G is a constituent of some power chi(n) of chi. Fifty years after
this appeared, Steinberg generalized it to a result on semigroup algeb
ras K[G] with K an arbitrary field and with G a semigroup, finite or i
nfinite. Five years later, Rieffel showed that the theorem really conc
erns bialgebras and Hopf algebras. In this note, we simplify and ampli
fy the latter work.