The Department of Legislative Services is out with its analysis of Gov. Martin O'Malley's proposal to expand and overhaul Maryland's gambling program, with the key element, politically anyway, the addition of a sixth casino in Prince George's County. Based on what DLS found, it is now quite clear why Prince George's County Executive Rushern Baker is in favor of this effort. It's obvious why the developer of National Harbor, the preferred site for a new casino, wants it, and why MGM is lined up to operate that facility if it opens. It's a great deal for them.