In his editing for the 1837 edition, Joseph Smith sometimes removed the past-tense modal verb might if it could be misinterpreted as having a conditional sense. As explained under Jacob 5:13, such uses of might in the original text will be restored in the critical text.
Summary: Restore the past-tense modal form might in Alma 13:26; the nonconditional use of might is found elsewhere in the original text.