effect at the time Simmons committed his offense, or the 2002 Guidelines, which were in effect on the date of his sentencing. Federal law requires judges presumptively to apply the sentencing Guidelines as they exist at the time of sentencing. 18 U.S.C. § 3553(a) (“The court, in determining the particular sentence to be imposed, shall consider ... the kinds of sentence and the sentencing range ... set forth in the guidelines ... that ... are in effect on the date the defendant is sentenced-”). The Constitution’s Ex Post Facto Clause, however, prevents the Government from imposing additional penalties for crimes that have already been committed. See U.S. Const, art. I. § 9, cl. 3 (“No ... ex post facto Law shall be passed.”); Calder v. Bull, 3 U.S. (3 Dall.) 386, 390, 1 L.Ed. 648 (1798) (<HOLDING>). Consequently, although courts must
holding that a change in parole law violates the ex post facto clause if the change in the law created a sufficient risk of increasing the measure of punishment attached to the covered crimes holding that the fact that a retroactive law may have a deleterious effect on an individual does not mean that it is ex post facto punishment holding that one way in which the ex post facto provision of the constitution can be violated is by applying a law that makes more burdensome the punishment of a crime after its commission holding that every law that changes the punishment and inflicts a greater punishment than the law annexed to the crime when committed is an ex post facto law within the words and the intent of the prohibition holding that an ex post facto claim can only be successful if the law can be characterized as punishment in the constitutional sense