James attended the University of Wisconsin in Madison, and played for the Wisconsin Badgers football team from 2001 to 2004. He played on the defensive line alongside teammate Anttaj Hawthorne. He finished his career with 124 tackles (25.5 for losses), 18 sacks, 28 quarterback hurries, seven forced fumbles, two fumble recoveries, and six pass deflections. James was nicknamed "The Eraser" for his ability to sack opposing quarterbacks. He was a first-team All-Big Ten selection and was recognized as a consensus first-team All-American following his senior season in 2004.
James was drafted by the Minnesota Vikings 18th overall in the 2005 NFL Draft. During his rookie year, he compiled 28 total tackles and four sacks. James missed most of the 2006 and 2007 seasons with injuries. The Vikings made their intentions clear to waive James on May 23, 2008, but later rescinded the waiver after the Washington Redskins offered a conditional 2009 seventh-round draft choice. He finished his injury-plagued career with the Vikings with 37 tackles and 5 sacks.
On May 27, 2008, the Vikings agreed to trade James to the Washington Redskins for a conditional seventh-round pick in the 2009 NFL Draft. He appeared in five games for the Redskins in 2008 but did not record any statistics and was eventually waived on December 9, 2008.