I'm not buying into any Tulane hype, or that the Green Wave should be a favorite against Houston. The Cougars have one of the top dual threat QB's in the nation in D'Eriq King, who accounted for 50 touchdowns last season and is getting more comfortable operating Dana Holgorsen's offense. Tulane's Justin McMillan is better than some past Tulane QB's and he has a deep group of running backs and wide receivers. But King has plenty of help, too, especially with the return of running back Patrick Carr. 
Tulane just played Missouri State this past Saturday. That was a cupcake opponent. Houston's statistics are skewed, especially defensively, by having already played high-powered fourth-ranked Oklahoma and 19th-ranked Washington State. So this is a drop in class for the Cougars, who covered against both of those Top-25 opponents. 
The Cougars rolled past Tulane, 48-17, at home last season. The Cougars were favored by seven in that game. During the previous four seasons from 2014-2017, the Cougars were favored by eight, 27, 21 and 17 points against Tulane. Houston has covered in six of its last seven trips to Tulane. 
Now the Green Wave not only is expected to beat the Cougars but cover a mid-size margin doing it. I'm not drinking that Kool-Aid.