The Anomalous Microwave Emission (AME) is a broad excess of diffuse Galactic radiation peaking between 10-60 GHz, first detected by COBE and confirmed by Planck/WMAP. Standard synchrotron and thermal dust models fail to explain its spectrum. The leading hypothesis is "spinning dust"—electric dipole radiation from ultra-rapidly rotating (tens of GHz) nano-grains (e.g., PAHs). However, significant uncertainties remain regarding the grain size distribution, dipole moments, and environmental dependencies required to fit the data. Furthermore, the polarization fraction of AME is observed to be extremely low ($\Pi < 1\%$), significantly below theoretical predictions for some aligned spinning dust models, and correlations with other ISM tracers (PAHs vs. thermal dust) are not always consistent (Dickinson et al. 2018; Hensley et al. 2016).