The Collaborative International Dictionary of English v.0.48:

Suffragate \Suf"fra*gate\, v. i. & t. [imp. & p. p.
   Suffragated; p. pr. & vb. n. Suffragating.] [L.
   suffragatus, p. p. of suffragari. See Suffragan, a.]
   To vote or vote with. [Obs.] "Suffragating tribes." --Dryden.
   [1913 Webster]