  Motivated by the remarkable discovery of superconductivity in elemental
Bismuth, we study its normal state in detail using a combination of
tight-binding (TB) and-structural supplemented by dynamical mean-field theory
(DMFT). We show that a two-fluid model composed of preformed and dynamically
fluctuating excitons coupled to a tiny number of carriers provides a unified
rationalization of a range of ill-understood normal state spectral and
transport data. Based on these, we propose that resonant scattering involving a
very low density of renormalized carriers and the excitonic liquid drives
logarithmic enhancement of vertex corrections, boosting superconductivity in
$Bi$. A confirmatory test for our proposal would be the experimental
verification of an excitonic semiconductor with electronic nematicity as a
`competing order' on inducing a semi-metal-to semiconductor transition in $Bi$
by an external perturbation like pressure.
