  Polarized pp elastic scattering at small angles in the Coulomb-nuclear
interference (CNI) region offers a unique opportunity to study the spin
structure of the Pomeron. Electromagnetic effects in elastic amplitude can be
equivalently treated either as Coulomb corrections to the hadronic amplitude
(Coulomb phase), or as absorption corrections to the Coulomb scattering
amplitude. We perform the first calculation of the Coulomb phase for the
spin-flip amplitude and found it significantly exceeding the widely used
non-flip Coulomb phase. The alternative description in terms of absorption
corrections, though equivalent, turned out to be a more adequate approach for
the Coulomb corrected spin-flip amplitude. Inspired by the recent high
statistics measurements of single-spin asymmetry in the fixed-target HJET
experiment at the BNL, we also performed a Regge analysis of data, aiming at
disentangling the Pomeron contribution. However, in spite of an exceptional
accuracy of the data, they do not allow to single out the Pomeron term, which
strongly correlates with the major sub-leading Reggeons. A stable solution can
be accessed only by making additional ad hoc assumptions, e.g. assuming the
Pomeron to be a simple Regge pole, or fixing some unknown parameters.
Otherwise, in addition to the STAR data at $\sqrt{s}=$200 GeV new measurements,
say at 100 GeV or 500 GeV, could become decisive.
