80% of U.S. crime due to Gangs, primarily drug gangs?

USA Today has this piece:

Criminal gangs in the USA have swelled to an estimated 1 million members responsible for up to 80% of crimes in communities across the nation, according to a gang threat assessment compiled by federal officials.

The major findings in a report by the Justice Department's National Gang Intelligence Center, which has not been publicly released, conclude gangs are the "primary retail-level distributors of most illicit drugs" and several are "capable" of competing with major U.S.-based Mexican drug-trafficking organizations. . . . .