Cornyn created the Texas Internet Bureau to investigate illegal internet practices.
He fought government waste and corruption by investigating fraudulent Medicare and Medicaid claims.

Cornyn was criticized by civil rights groups for failing to investigate in a timely manner the false drug convictions of numerous African-Americans in Tulia, Texas.
On September 6, 2002, the Austin Chronicle reported that Cornyn had announced that his office would investigate the 1999 drug bust, where the testimony of one narcotics agent led to the arrests of 46 people, 43 of whom were Black.

In 2005, Cornyn was mentioned as a possible replacement for Supreme Court Justices Sandra Day O'Connor and William Rehnquist.
Cornyn created the Texas Internet Bureau to investigate illegal internet practices. He fought government waste and corruption by investigating fraudulent Medicare and Medicaid claims.
Cornyn was criticized by civil rights groups for failing to investigate in a timely manner the false drug convictions of numerous African-Americans in Tulia, Texas. On September 6, 2002, the Austin Chronicle reported that Cornyn had announced that his office would investigate the 1999 drug bust, where the testimony of one narcotics agent led to the arrests of 46 people, 43 of whom were Black.
In 2005, Cornyn was mentioned as a possible replacement for Supreme Court Justices Sandra Day O'Connor and William Rehnquist.
John Cornyn