MADISON, Wis. (AP) – Wisconsin’s Melvin Gordon and James White are making a strong case for being the top running back tandem in the country.  The Badgers ran past Purdue in a 41-10 victory this weekend thanks in part to 147 yards and three touchdowns from Gordon, and 145 and a 70-yard score from White. Wisconsin moved up on one spot to No. 23 in Sunday’s AP Top 25 poll.  Gordon averages 156 yards rushing a game. But besides a Week 3 game against Arizona State, the defenses the Badgers have faced so far have been suspect at best.  The competition level goes up a few notches next weekend when Wisconsin visits the Horseshoe for a prime-time showdown with fourth-ranked Ohio State.