  We introduce a novel mechanism for the unusual itinerant ferromagnetism found
in mixed valence systems like Ce(Rh$_{1-x}$Ru$_x$)$_3$B$_2$,
La$_x$Ce$_{1-x}$Rh$_3$B$_2$, US, USe, and UTe. With it we can provide an
explanation for the long-unexplained large value of $T_c$ ($\sim$ 100$^\circ$K)
value and the maximum in the magnetization below $T_c$ found experimentally. We
also show that this novel itinerent ferromagnetism can be continuously
connected with the localized case for which the energy scale is much smaller
($J_{RKKY} \sim$ 1$^\circ$K).
