Republican Senator Jon Kyl said Barack Obama's willingness to negotiate with Iran shows ``weak judgment,'' signaling his party will likely focus on portraying the Democratic presidential candidate as naive about rogue nations. Obama's stance of holding talks ``without preconditions'' with Iranian President Mahmoud Ahmadinejad ``shows weak judgment, and frankly, naivete,'' Kyl, the No. 2 Republican leader in the Senate, said on ``Fox News Sunday.''