The nucleon isovector Pauli radius R2V2 is calculated, using sidewise dispersion relations, to be significantly larger than the predictions of dominance, in accord with observation. It is also predicted that R2V2 is significantly larger than the pion charge radius R2. Elastic scattering of pions from electrons at very high energies (viz. Serpukhov) will give a clear confrontation with this prediction. © 1968 The American Physical Society.