That's from the Thompson Campaign, as reported by K-Lo at The Corner.

Which makes Romney the only top tier candidate who does support the Federal Marriage Amendment.  (Romney's very public campaign on behalf of the Amendment is detailed in A Mormon In The White House.)

Thompson leaves the door open to supporting the amendment in the future, but proponents of the amendment have long pointed to the threat of sudden, judge-imposed changes in the law that would see DOMA struck down without warning.

This is a huge issue in the GOP primaries with a crucial segment of the electorate --the segment that hates court-imposed social engineering.  Fred Thompson's lassitude on this issue will undercut the enthusiasm some in the evangelical community have expressed for his possible candidacy. 

If the defense of traditional marriage is one of your key issues, Fred Thompson can't be your candidate.