The contracting firm that is constructing the new Save Mart supermarket and Tractor Supply Co. in Manteca — and is in a partnership with the Brocchini Family Trust — is being slammed by mayoral hopeful Jacob Naven for supporting efforts to re-elect incumbent Gary Singh. The reason? The Sonora-based firm — California Gold Development — built a 19,000 square-foot office building for the Immigration Customs Enforcement (ICE) agency in Reno. The work was completed in 2010.