Jackson went to Minnesota where they thought he could be the answer to all of their problems. Before the 2006 draft, Brad Childress said that he wanted to find a "diamond in the rough"—someone he could work with and teach the system, similar to A.J. Feeley and Donovan McNabb.
It took Jackson until the end of his third season with the Vikings to do something worthy when he beat the Cardinals in 2008. He isn't the one who got the Vikings the NFC North title that season, that was thanks to Gus Frerotte, but he was the one who ended the playoff run.
The next two seasons, Jackson was at Minnesota he was the second QB behind Brett Favre—a situation where he should have improved his game. So far that has not seemed to be the case.