WASHINGTON (AP) — Mayor Vincent Gray often calls the District of Columbia “the envy of the nation” for its robust economy and fast-growing population, but some say the local government he leads — plagued by corruption, pay-to-play politics and disengaged voters — is a stain on the city’s progress.

The latest bruise to the city’s reputation involves Gray, who is under federal investigation. Prosecutors say he knew about a $668,000 campaign slush fund that helped him get elected in 2010, and while Gray has not been charged, five people involved with his campaign have been convicted. Separately, three former members of the D.C. Council have pleaded guilty to felonies, including bribery and embezzlement, in less than 2 ½ years.