  We show that the density and temperature dependences of the
$\alpha$-relaxation time of several glassforming polymers can be described
through a single scaling variable $X=e(\rho)/T$, where $e(\rho)$ is well fitted
by a power law $\rho^x$, $x$ being a species-specific parameter. This implies
that ``fragility'' is an intrinsic, density-independent property of a
glassformer characterizing its super-Arrhenius slowing down of relaxations, and
it leads us to propose a modification of the celebrated Angell plot.
