SOUTH BEND - In chalk on the sidewalk, on signs taped to doors on campus buildings, even seemingly blowing through the semi-arctic breeze, the message pervaded every corner of campus.

Even Notre Dame head football coach Charlie Weis’ bunker in the Gugilelmino Athletics Complex.

“We believe!"

“I haven’t felt it like this ever since I’ve been here,” Weis said of the thickness and intensity of the pregame buzz for Saturday’s Notre Dame Stadium showdown between the 25th-ranked Irish (4-1) and No. 6 USC (4-1).

“Every player and every person who works in the building - and it’s not just the university - it’s the town. Everyone’s looking forward to this game.”

Maybe no one more than Irish senior strong safety Kyle McCarthy, who was so wound up for the game on Wednesday that he actually thought it was Thursday.

And perhaps no player on the team needed to be reminded less about believing than McCarthy.

The 6-foot, 210-pound fifth-year senior, ND’s leading tackler and momentum-twister, embodies it.

It’s not just because he came in with a disheveled recruiting class, hastily duct-taped together by Weis after coach Tyrone Willingham’s dismissal late in 2004. It’s a class whose only two prospects rated higher than ho-hum three stars gave up football (tight end Joey Hiben) or transferred to an Football Championship Subdivision school (Northern Iowa wide receiver D.J. Hord).

It’s not just that the former all-state option quarterback for Ohio state champion Youngstown Cardinal Mooney showed up tipping the scales at 165 pounds, then had his weight-lifting regimen escrowed because of shoulder surgery.
It’s that he was living a dream for two - himself and his grandpa, Jack Mayo.

Mayo is a former Notre Dame baseball captain who played for the Irish in the mid-’40s

“I was a brainwashed Notre Dame fan diehard,” McCarthy, captain of the Irish defense, said with a smile. “Just being an Irish Catholic kid, last name McCarthy, I didn't really have a chance.”

Nor did McCarthy have a chance to do anything but keep the faith when his playing time his first two seasons amounted to a grand total of two minutes, 47 seconds, or when Weis recruited over McCarthy with safeties with prettier pedigree (including his younger brother, Dan), or when he had to step into former Irish All-American Tom Zbikowski’s dynamic tract when the latter moved on to the NFL.

“I wouldn’t say I was worried or intimidated by any of it,” McCarthy said. “I would say it just fueled the fire. It made me work harder in the offseason.”

And fueling the fire was Mayo.

“He’s been a huge role model for me in athletics and my personal life,” McCarthy said. “He’s been ill and it doesn’t look like he is going to be able to make it to the game, but I hope he does. He means an awful lot to me.”

As does McCarthy to the Notre Dame defense.

Beyond his team-leading 49 tackles - 17 more than No. 2 on the list, free safety Harrison Smith - McCarthy snuffed out Michigan State’s potential game-winning rally on Sept. 19 with a last-minute interception, then teamed with Smith on a concussion-causing pass breakup in overtime Oct. 3 against Washington.

“He’s a guy who’s been here for five years now,” Smith said of McCarthy. “Just being here that long, you accumulate knowledge that you can pass on to other guys. Him being out there gives you confidence, because you know he’s going to be in the right spot.”
The same can’t be said of the Irish defense as a whole. Notre Dame is 100th out of 120 nationally in total defense, though some brilliant streaks of dominance have been mixed in with the large swaths of inconsistency.

ND’s No. 4 national ranking in red-zone defense hints at where the ceiling of this defense could be. So do burgeoning playmakers such as freshman linebacker Manti Te’o, sophomore linebacker Darius Fleming, sophomore defensive tackle Ethan Johnson and sophomore defensive end Kapron Lewis-Moore.

But how fast, how soon?

And how do they get past the mental hurdles of complete domination by the Trojans in the past two meetings, won by USC by a combined 76-3.

“We're a different team this year, just as USC is a different team this year than they were last year,” McCarthy said. “We have different guys. We have new leaders on this team. We have younger guys that have stepped up into a leadership role and worked hard in the offseason. I think that's shown on the field this year.

“Just this team has become real close over the last couple years. We've all grown and matured.”

And Saturday the college football world will gets its first distortion-free view of what this team has grown into.

The dynamic of Weis’ future, the skid marks on ND’s psyche of the past two meetings, the re-anointing of Irish quarterback Jimmy Clausen all make this ND-USC clash different.

There is a disconnect from the Knute Rockne and Anthony Davis references, and even those of Gerry Faust and Ted Tollner.

This is about where the ugliness of this program has been the past couple of years and where it’s headed beyond 2009.

“I just got done talking to the team,” Weis said Thursday evening. “I said, ‘Saturday night you’re going to be the lead story in the country one way or another. So which lead story do you want to be?’ ”

We believe?

“One of the reasons we came to Notre Dame is to play in games like this,” McCarthy said. “Sure, we had bumps in the road the last couple years, but we're back in the national spotlight. We have some things to prove.

“We feel confident going out every day, and we think that we can improve every week. Hopefully, it shows Saturday.”