Texas Election Code - ELEC § 221.011. Illegal Votes Subtracted

(a) If the tribunal hearing an election contest can ascertain the candidate or side of a measure for which an illegal vote was cast, the tribunal shall subtract the vote from the official total for the candidate or side of the measure, as applicable.

(b) If the tribunal finds that illegal votes were cast but cannot ascertain how the voters voted, the tribunal shall consider those votes in making its judgment.