John McStain's dad was a 33rd degree mason at Lodge #11, St John's Lodge, in Washington DC.

McCain was made a Mason On Sight in 1975. He was a member of St. John's Lodge No. 11 and received his 33rd degree.

https://www.masonrytoday.com/index.php?new_month=1&new_day=17&new_year=2015

https://www.dcgrandlodge.org/lodge-locator.html