Yes and no.
U.S. Const., Art. I, Sec. 9, Cl. 3:
"...
No Bill of Attainder or ex post facto Law shall be passed.
..."
The federal ex post facto law clause.
U.S. Const., Art. I, Sec. 10, Cl. 1:
"No State shall enter into any Treaty, Alliance, or Confederation; grant Letters of Marque and Reprisal; coin Money; emit Bills of Credit; make any Thing but gold and silver Coin a Tender in Payment of Debts; pass any Bill of Attainder, ex post facto Law, or Law impairing the Obligation of Contracts, or grant any Title of Nobility."
The State ex post facto law clause.
You may be confused as to the qualification in Constitutional law as to ex post facto laws ("after the fact"), in that Calder v. Bull, 3 U.S. 386 (1798) held that this provision applied only to criminal cases. The provision has been held to disallow both laws criminalizing conduct and laws decriminalizing conduct.
Other exceptions have formed in Constitutional law over the years, particularly recently, too.
SORNA passed. so the answer is yes.
SORNA passed. so the answer is yes.
SORNA passed. so the answer is yes.
For all practical purposes, No. However, technically speaking, if Congress chose to pass an ex-post-facto law (either by 2/3rd in both houses to overrule Presidential Veto power or even if a President were to sign it) the law would be deemed Unconstitutional by the Supreme Court once challenged - hence the beauty of the checks-and-balances system in the United States. In practical terms it would, however, mean that the law would be in force for a period of time until the case challenging it would reach the Supreme Court for review.The only way to make an ex-post-facto law actually stick would be, in effect, to amend the Constitution.
No. Article I, Section 9, paragraph 3 of the Constitution prohibits Congress from passing ex post facto laws.
yes
passing ex post facto laws
ex post facto laws and Bills of Attainder
false
Ex Post Facto law "Congress shall pass no Ex Post Facto law", I believe is how it appears in the constitution. It is latin for after the fact.
Ex post facto :)
(in the US) No. The question is an untrue statement.