Senate votes to tighten sanctions on Iran from AP Top Political News At 5:39 a.m. EST by By DONNA CASSATA WASHINGTON (AP) -- The Senate endorsed stringent new sanctions on Iran's energy and shipping sectors in a fresh attempt to hobble the Islamic Republic's economy and hamper its nuclear ambitions.... hosted.ap.org/dynamic/stories/U/US_DEFENSE_BILL?SITE=TXHAR&SECTION=HOME&TEMPLATE=DEFAULT