The mascot of the University of Notre Dame (in South Bend, Indiana) is "the Fighting Irish," and yes, I realize how incredibly contradictory that statement is. They are also the original bandwagon establishment team in college football, dating back nearly a century to when Norwegian-American Knute Rockne perfected the spiral and led them to a shocking upset of the US Army academy. Combined with the fact the college football still ELECTS its champion, that has evidently "earned" Notre Dame the #1 ranking (though saying ANY Division 1A football team earned ANYTHING is a rather dubious statement.)

Basically, Division 1A college football has over 100 teams, but only respects about a dozen (and none more than Notre Dame,) and its annual campaign to elect one of them "national champion" has paid off handsomely for Irish fans. Go, Elected Champions; call me when you get a playoff system and I might actually care.

Believe it or not, that really is the short form; it is hard to encapsulate ~140 years of college football in two paragraphs.