By Andrew McCarty On Thursday night, Michigan head coach Jim Harbaugh said he is done chasing an NFL head coaching job. “Sure, the Super Bowl is the greatest prize in our sport,” he said in a conversation with Mitch Albom of the Detroit Free Press. “But winning a national championship. That’s pretty darn great. Let’s do that.” Harbaugh admitted there is a “pull” from the NFL, but now he’s ready to focus on bringing a national championship to Ann Arbor. “There was a pull to the NFL because I got that close to the Super Bowl,” he said. “But this was the time (to try and return.) And this is the …