Depends upon your time frame, both looking backward and ahead. When I started watching (actually listening to them) they had just been defeated in the Rose Bowl jan1, 1941 by a team using a new formation that we could't solve (the T formation). Minnesota was champion of the country at that time, and we reguarly had good hard fought games with them. Then there was the drought during the 40s when winning something like five games was a good year.
Then Devaney came in and made full use of players that usually could not qualify for admission, a new kind of muscle building and endurance building approach, 100 plus scholarship players, etc., and we were pretty good again, even winning a mythical Nattie in 70-71. TO carred that forward though he had a very difficult time beating Oklahoma. He retired from coaching in 1997 after assembling truly great teams and it hasn't been the same since.
So which mojo are you talking about. I don't want them to continue with the current revival of their miserable seasons in the 40s and fities even though at one time that was kind of their mojo.
I'd like to see them get back to consistent 8 - 10 win seasons with a good upset or two every year. I think that's doable though not every year. We'll get an inkling if this staff in this environment now can do that.
But as for getting our mojo back,if you mean a national champion contender regularly, probably not. We had real advantages in those days that we most likely cannot get again.
Only if you will only be satisfied with undefeated seasons will a regular 8 -10 win season be seen as underperforming.