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We present the first near-IR spectroscopy of the z=1.5 radio-loud BALQSOFIRST J155633.8+351758. Both the Balmer decrement and the slope of therest-frame UV-optical continuum independently suggest a modest amount ofextinction along the line of sight to the BLR (E(B-V)~0.5 for SMC-type screenextinction at the QSO redshift). The implied gas column density along the lineof sight is much less than is implied by the weak X-ray flux of the object,suggesting that either the BLR and BAL region have a low dust-to-gas ratio, orthat the rest-frame optical light encounters significantly lower mean columndensity lines of sight than the X-ray emission. From the rest-frame UV-opticalspectrum, we are able to constrain the stellar mass content of the system.Comparing the maximal stellar mass with the black hole mass estimated from thebolometric luminosity of the QSO, we find that the ratio of the black hole tostellar mass may be comparable to the Magorrian value, which would imply thatthe Magorrian relation is already in place at z=1.5. However, multiple factorsfavor a much larger black hole to stellar mass ratio. This would imply that ifthe Magorrian relation characterizes the late history of QSOs, and thesituation observed for F1556+3517 is typical of the early evolutionary historyof QSOs, central black hole masses develop more rapidly than bulge masses.[ABRIDGED]Comment: 23 pages, 4 embedded postscript figures; Accepted for publication in  The Astronomical Journal, December 200

Red Quasars and Quasar Evolution: The Case of BAL QSO FIRST J155633.8+351758