BOCA RATON — John Kerry addressed a packed house Monday morning at a private event in Boca Raton, urging supporters of Democratic presidential hopeful Joe Biden to keep working to get the vote out right up until the last minute. “Nothing is automatic in politics,” Kerry said, reminding the crowd of his own ill-fated presidential bid 16 years ago. “This is not to be taken for granted. You have to make phone calls, sign up and do the work.” After losing the 2004 election to incumbent President George W. Bush, Kerry, then a former Massachusetts U.S. senator, went on to...