On The Warpath Meaning

(idiomatic) Very angry or upset.

Example: 1932, "Religion: Churches v. Council," Time, 6 June:
  Last year a committee of the Federal Council of the Churches of Christ in America issued a report guardedly approving Birth Control. . . . [M]any Presbyterians heartily disapproved. Last week the Presbyterian General Assembly met in Denver with Philadelphia's Rev. H. McAllister Griffiths and a corps of Fundamentalists on the warpath.
2006, Colin Brown, "Fears grow for waterways as canal jobs are cut," The Independent (UK), 11 Oct.:
  Boating enthusiasts, walkers and others who enjoy relaxing by canals were on the warpath last night after British Waterways announced plans to cut 180 staff.