Standardized testing in Texas has a long history. It predates even the George W. Bush governorship in the 1990s. Standardized testing and accountability was given credit for narrowing the achievement gap between whites and minorities. The New York Times had good things to say about Texas in 1999 when Governor Bush was leveraging Texas's reputation in his own bid for the White House.
This has stemmed partly from a unique accountability system that predates Mr. Bush's tenure and requires all Texas schools to give an array of standardized tests and record the results for each subgroup -- white, black, Hispanic and economically disadvantaged. The schools are judged on the performance of each group separately. Other states give tests but no other uses the performance of subgroups separately to determine success.
Source: New York Times, May 28, 1999.