Addressing a crowd of more than 200 gathered on a factory floor in Burlington in southeast Iowa, the potential 2016 candidate expressed his full-throated support for Branstad, who is far ahead in the polls. The visit marked Christie's fourth to the early-voting state in recent months and his second of the week, giving him yet another chance to court caucus voters ahead of a potential presidential run. [...] Christie, who is in his final stretch as chairman of the Republican Governors Association, used the opportunity to shower his Republican counterpart with praise, comparing Branstad to a baseball legend and describing him as a role model and "seasoned, selfless leader" who sets goals and achieves them.