[R]elying on a close examination of recent Texas elections, it concluded that the plan would reduce the ability of minority voters to effectively participate in the political process, the test for discriminatory effect under Section 5 [the "preclearance" requirement of the Voting Rights Act, to which Texas among other southern states is subject].
More specifically, according to the memorandum, the plan failed to pass muster under each and every factor the Supreme Court has established for gauging whether or not a redistricting plan will reduce minority electoral opportunity. This was not a close case.
A unanimous recommendation like this would ordinarily have been affirmed by the DOJ's politically appointed higher-ups. But this one wasn't. "The Texas case provides another example of conflict between political appointees and many of the division's career employees," according to the Washington Post. Indeed. As a better Texas politician said to George Wallace in 1965 for his part in the oppressive violence that led to the Voting Rights Act in the first place, "Shame on you," Tom DeLay.