Last year we had a very big drop so #80 seems lateral to me.
TCU's been in the USN&WR 80-100 range for at least 3 decades now (we had a drop in '94 to a tie for #103 I believe.) Dr Tucker at the time said the drop was largely due to our "freshmen retention rate" and that was when they doubled-down on an emphasis of engaging the new students pre-enrollment (like Frog Camp) to get the kids connected. It apparently returned us to the 80-something range.
As an observer of this "list" (since USN&WR had been one of my clients over the years) TCU's height has been slowed by the "nationalization" of what they used to describe as "Regional Universities." -Several of these schools have jumped in front of us once they are deemed "National."
Wake Forest,#28, Brandeis #42, Santa Clara #53, Villanova #53, Loyola Marymount, #66 Worcester Polytechnic #76, Yeshiva #76, Gonzaga #80, Stevens Institute #80 are all examples of this effect.
On our heels are several other former "Regional" universities:
ColSchMines #88, Elon #88, Clark (MA) #103, USF #103, LaVerne (CA) #112 (what, who, where? "national" really!)
I'd just be happy to jump Baptist Tech and SnootyDallasU.
(All of those Uof Cali campuses in the Top 100 - it doesn't seem fair.)