But it should not even get to the argument of “personal property” if it indeed is an ex post facto law, which would be unconstitutional.
In the United States, ex post facto laws are prohibited in federal law by Article I, section 9 of the U.S. Constitution and in state law by section 10. Over the years, when deciding ex post facto cases, the United States Supreme Court has referred repeatedly to its ruling in the Calder v. Bull case of 1798, in which Justice Chase established four categories of unconstitutional ex post facto laws. The case dealt with Article I, section 10, since it dealt with a Connecticut state law.
http://en.wikipedia.org/wiki/Ex_post_facto_law
We all remember the "what the meaning of is, is" crap, which is EXACTLY what is being done with re-inventing and destroying the U.S. Constitution, too.