The Collaborative International Dictionary of English v.0.48:

Militate \Mil"i*tate\, v. i. [imp. & p. p. Militated; p. pr. &
   vb. n. Militating.] [L. militare, militatum, to be a
   soldier, fr. miles, militis, soldier.]
   To make war; to fight; to contend; -- usually followed by
   against and with.
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         These are great questions, where great names militate
         against each other.                      --Burke.
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         The invisible powers of heaven seemed to militate on
         the side of the pious emperor.           --Gibbon.
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