From 2009 to 2017, Stanford was Notre Dame’s most aggravating rival. The history of the USC rivalry may go back many more decades, and the Irish hate of Michigan may be based on its inarguable proximity, but it was the Cardinal beating out Notre Dame for recruits and then beating the Irish with them seven times in nine years.
These were supposed to be the two programs competing for football prominence but not at the expense of academic excellence, and one of them was doing it much better. Stanford won 10.3 games per year in those nine seasons, while Notre Dame managed 8.