The two Senate leaders also ask why the U.S. attorney in New York on April 15 secured indictments against the operator of an online gambling site after taking no action for several years.
The U.S. attorney in Baltimore unveiled additional indictments at the end of May.
"This lack of activity by law enforcement led to a significant and growing perception that operating Internet poker and other Internet gambling did not violate U.S. laws, or at least that the Department of Justice thought that the case was uncertain enough that it choose not to pursue enforcement actions," according to the letter dated July 14.