21. This claim was based on the constitutional prohibition against bills of attainder and ex post facto legislation. 22. The bill of attainder is an ancient and infamous device forbidden by the U . S . Constitution. 23. This, he said, violates the constitutional prohibitions against bills of attainder and ex post facto laws. 24. Bills of attainder are considered permissible because there is no entrenched separation of powers at the state level.25. It was also possible, as political fortunes turned, for a bill of attainder to be reversed. 26. Can it be said, that congress may pass a bill of attainder for the district of Columbia? 27. Sir John Fenwick was convicted on a bill of attainder , and was executed on 28 January 1697. 28. Exxon claimed OPA was effectively a bill of attainder , a regulation that was unfairly directed at Exxon alone. 29. Parliament passed a bill of attainder against the ringleader, John Fenwick, and he was beheaded in 1697. 30. Since the Los Angeles ordinance permitted no hearing, it was a bill of attainder and not constitutionally valid.
