Poly(3,4-ethylenedioxythiophene) (PEDOT) is a highly stable electroactive polymer used in a variety of applications ranging from electrochromics, to charge storage, to biomedical materials. In order to obtain a polymer that can be solution processed but retains the desirable properties of PEDOT, we have designed a soluble polymer by copolymerizing EDOT with a solubilizing 3,4-propylenedioxythiophene derivative, bearing ester functionalized side chains. This polymer was synthesized in excellent yield using direct arylation polymerization. Chemical defunctionalization of the polymer using potassium hydroxide to hydrolyze the esters yields a conjugated polyelectrolyte that is readily soluble in water. This aqueous soluble polyelectrolyte has been processed using roll-to-roll compatible methods such as spray coating. Post processing functionalization of the polymer film using dilute acid creates a solvent resistant film that is compatible with both organic and aqueous electrolyte solutions for redox switching. The introduction of EDOT to the ProDOT backbone lowers the oxidation potential and, as a result, broadens the potential window this polymer is electroactive in, approaching that of PEDOT. Not only is this copolymer active over a broad voltage range (2V in organic and 1.55V in aqueous solvents) but also highly capacitive, making it an attractive material for lightweight and flexible supercapacitors. These films demonstrate exceptionally rapid switching (up to 2000mV/s) compared to similar polymers using typical aliphatic side chains in both organic (LiBTI/PC) and aqueous (LiBTI or NaCl/Water) electrolyte solutions. There is little change in the mass capacitance of thin films of this polymer when switching from organic (58F/g) to aqueous (55F/g) systems while using LiBTI as the electrolyte. Changing to a NaCl electrolyte solution shows only a moderate decrease in the mass capacitance to 46F/g. The versatility of this polymer is shown in a series of organic and aqueous electrolyte systems, including environmentally benign electrolytes such as sodium chloride and Gatorade™. A series of biological electrolyte solutions, such as blood, have also been investigated. Based on these results, it is clear that this polymer and similar systems have great potential in electrochromic, supercapacitor, and bioelectronics applications.