Tex. Est. Code § 123.103
(a) Except as provided by Subsection (b), in a proceeding brought under Section 123.102, the court shall declare the decedent's marriage void if the court finds that, on the date the marriage occurred, the decedent did not have the mental capacity to:
(b) A court that makes a finding described by Subsection (a) may not declare the decedent's marriage void if the court finds that, after the date the marriage occurred, the decedent:
Added by Acts 2009, 81st Leg., R.S., Ch. 680, Sec. 1, eff. January 1, 2014.