. >>> president obama haled the senate's iran vote as a victory. they tried to block the vote. now republicans and the house of representatives say they will pursue a legal challenge to the nuclear agreement. >>> the u.s. says it's deeply troubled by the conviction of venezuela's opposition leader. he's been sentenced to 14 years in jail for insighting violence during last year's antigovernment protest. 40 people were killed. his supporters say he's being used by the president as a distraction from the ongoing economic crisis. >>> polls have opened in singapore in what's expected to be the most competitive election in decades. they have been in power for 50 years. but for the first time a huge number of voters born after the country's independence will be taking part. and that could change the outcome. we have more now from singapore. >> voting has been brisk throughout this island republic. there was already a line of people waiting when the gates first opened at 8:00 in the morning. this is the east coast constituency. it is very marginally fought between the ruling party and