KENOSHA, Wis. (AP) – Rob Zerban, the Democratic challenger who lost to Congressman Paul Ryan last year, says he’ll try again next year to unseat the eight-term Republican congressman.  Zerban told The Associated Press on Thursday he will mount a second challenge in 2014. He’ll announce his candidacy formally Saturday in Kenosha.  The 45-year-old served two terms on the Kenosha County Board and is a former small-business owner. He says he spent the last year meeting voters in southeastern Wisconsin, and he’s convinced they want a representative who focuses on creating jobs and protecting the poor. He says they’re not getting either from Ryan.  Ryan beat Zerban last year, 55 percent to 43 percent. It was Ryan’s smallest margin of victory since he first won in 1998. However, he remains a formidable fundraiser.