  The polarization of the Cosmic Microwave Background (CMB) is rich in
information but obscured by foreground emission from the Milky Way's
interstellar medium (ISM). To uncover relationships between the underlying
turbulent ISM and the foreground power spectra, we simulated a suite of driven,
magnetized, turbulent models of the ISM, varying the fluid properties via the
sonic Mach number, $\mathcal{M_S}$ and magnetic (Alfv\'en) Mach
number,$\mathcal{M_A}$. We measure the power spectra of density ($\rho$),
velocity ($v$), magnetic field ($H$), total projected intensity ($T$),
parity-even polarization ($E$), and parity-odd polarization ($B$). We find that
the slopes of all six quantities increase with $\mathcal{M_S}$ Most increase
with $\mathcal{M_A}$, while the magnetic field spectrum steepens with $M_A$. By
comparing spectral slopes of $E$ and $B$ to those measured by Planck, we infer
typical values of $\mathcal{M_S}$ and $\mathcal{M_A}$ for the ISM. As the fluid
velocity increases, $\mathcal{M_S}> 4$, the ratio of BB power to EE power
increases to approach a constant value near the Planck-observed value of $\sim
0.5$, regardless of the magnetic field strength. We also examine
correlation-coefficients between projected quantities, and find that
$r^{\rm{TE}}\approx 0.3$, in agreement with Planck, for appropriate
combinations of $\mathcal{M_S}$ and $\mathcal{M_A}$. Finally, we consider
parity-violating correlations $r^{\rm{TB}}$ and $r^{\rm{EB}}.$
