What is the test for abuse of the writ?

An abuse of the writ will be found unless the petitioner can show cause for the failure to raise the contested claims in the first petition and prejudice if barred from bringing the claims in a successive petition. Id. at 1470. Cause exists where some objective external factor impeded the petitioner's raising of the new claims. Id. (citing Murray v. Carriger, 477 U.S. 478, 488 (1986)). Objective factors that constitute cause include (1) interference by state officials, (2) a showing that the factual or legal basis for a claim was not reasonably available, or (3) constitutionally ineffective assistance of counsel. Id. If the petitioner cannot show cause, no inquiry into prejudice need be made unless a fundamental miscarriage of justice is implicated. Id. at 1470, 1474.