Under what circumstances is successful post-conviction litigation a 'successful attack' on a prior state sentence?

QUESTION PRESENTED In Johnson v. United States, 544 U.S. 295 (2005), and Custis v. United States, 511 U.S. 485 (1994), this Court held that a defendant who “successfully attacks” a prior sentence or sentence may return to federal court to reopen a subsequent federal sentence that was enhanced on the basis of the prior sentence. Under what circumstances is successful post-conviction litigation a “successful attack” on a prior state sentence? ii RELATED CASES Eastern District of Wisconsin Doc. #134 U.S. v. Willie J. Newton, Jr. Case no. 00-cr-00242-LA-4 12/10/01 — judgment entered Eastern District of Wisconsin Doc. #7 U.S. v. Willie J. Newton, Jr. Case no. 14-C-739, 00-CR-242 8/29/14 — judgment entered Eastern District of Wisconsin Doc. #6 Willie J. Newton, Jr. v. US. Case no. 04-cv-00718-LA 10/25/04 — judgment entered Eastern District of Wisconsin Doc. #3 US. v. Willie Newton, Jr. Case no. 06-cv-01122-RTR 10/27/06 — judgment entered US. Court of Appeals for the Seventh Circuit US. v. Willie Newton, Jr. Case no. 07-1525 7/13/07 — judgment entered dismissing appeal US. Court of Appeals for the Seventh Circuit Doc. #17 U.S. v. Willie J. Newton, Jr. Case no. 17-3096 9/17/19 — judgment entered denying rehearing en banc