Guild President Alan Rosenberg told Daily Variety that McCord was a "polarizing influence" on the union.
McCord's election as national first vice president places him in charge of the meetings of SAG's huge Hollywood chapter, and marks a victory for union hardliners over Rosenberg's more-moderate style, Variety said.
The publication also said it underlined some unhappiness in the ranks over SAG's supposed slow movement on issues such as a franchise agreement with major talent agencies and competition for jurisdiction over shows with the AFTRA union.
McCord has been involved in union politics since the 1970s and defeated Rosenberg ally Anne-Marie Johnson for the national vice president post on a 17-16 vote by the SAG board.
2014: The Year in Music [PHOTOS]