NOVELTY - A fluorinated ionomeric copolymer comprises fluorinated backbone, pendant groups from ionomeric monomer, and pendant groups from vinyl ether monomer having at least 2 vinyl ether groups.    USE - The invention is used for making membrane. It is used in membrane electrode assembly having anode, cathode, and a membrane; and electrochemical cell with cathode feed with oxidizing species, anode feed having reducing species and membrane electrode assembly. (all claimed)    ADVANTAGE - The invention has a combination of very high ionic conductivity while maintaining relatively low hydration.    DETAILED DESCRIPTION - Fluorinated ionomeric co-polymer comprises fluorinated backbone, pendant groups from ionomeric monomer of the formula -(O-CF2-CF(CF2X))n-O-(CFRf)(CFRf')a(CF2)bY, and pendant groups from vinyl ether monomer having at least 2 vinyl ether groups of the form CA2=CB-O-.    The concentration of the pendant groups from ionomeric monomer and the vinyl ether monomer is between 10-45 mol.% of the final product. The concentration of the pendant groups from vinyl ether monomer is present in the final product between 0.05-2 mol.%.    X = F, Cl, and/or Br;    n = 0-2;    Rf, Rf' = F, Cl, perfluoroalkyl radical, or chloroperfluoroalkyl radical;    Y = acid group or functional group convertible to acid group;    a = at least0;    b = integer greater than 0;    a = F, Cl, or H;    B = F, Cl, H, or ORi; and    Ri = optionally branched chain alkane that may be partially or completely fluorinated or chlorinated.    INDEPENDENT CLAIMS are also included for the following:    (a) a process for making fluorinated polymer comprising forming mini-emulsion of mixture of deionized water, perfluorinated surfactant, optionally dissolved aqueous solution, and liquid perfluorinated hydrocarbon having molecular weight below 2000 and ionomeric monomer; pressurizing mini-emulsion in agitated reactor with fluorinated alkene gas; initiating polymerization with free radical initiator in reactor; maintaining known pressure of fluorinated alkene gas for period of time; and adding vinyl ether monomer during process step(s); and    (b) a membrane comprising porous support and fluorinated ionomer.    DESCRIPTION OF DRAWING(S) - The figure shows a cross sectional view of a fuel cell including an ionomer