New polymeric modifiers of electrophoretic systems have been synthesized. These are cationic polyelectrolytes with micellar properties: poly-11-acryloyloxyundecyl-1,4-diazobicyclo[2.2.2]octanium bromide and a chiral copolymer based on acylated quinine and N-(11-acryloyloxydecyl)-N-methylpiperidinium bromide. The electrophoretic capabilities of these polymers have been studied in the separation of model mixtures of steroid hormones and biogenic amines by capillary micellar electrokinetic chromatography and capillary electrochromatography methods. It has been found that the new polyelectrolytes serve as multifunctional modifiers of the bare fused silica capillary wall and background electrolyte, allow for the implementation of various mechanisms of electrophoretic and chromatographic separation, generate an anodic electroosmotic flow, and influence the separation efficiency and selectivity. It was discovered that the copolymer with quinine acting as a chiral label in the composition of two-phase chiral systems promotes the separation of the enantiomers of β-blockers propranolol and carvedilol.