CHICAGO — The Democratic National Convention kicked off Monday afternoon to rows and rows of empty seats — at least in part caused by pro-Palestine protests that stranded some delegates attempting to travel from downtown Chicago to the United Center, several miles away. Pro-Palestine protesters, some of whom attempted to break through security barriers ringing the United Center, clashed with law enforcement officers in the hour before the convention was scheduled to begin. At least 20 buses filled with members of Democratic National Convention state delegations stopped about a half mile short …