Not even the first-year coach thought it would happen in one year.
But it has.
South Carolina is alone atop its division in the Southeastern Conference and is playing before near capacity, raucous crowds. The Gamecocks need just two wins with three games to play to reach the improbable goal of winning at least a share of the SEC East.
"We're not there yet," Horn said. "We're getting to play for it right now which is great, which is ahead of schedule."
The Gamecocks have guaranteed just their third winning SEC season since joining the league in 1991. They have made the NCAA tournament only once this decade, but a second trip appears likely with one more win. Every 10-win team from the SEC eligible for the NCAAs has made it since the league expanded 18 years ago.
And all this has come from the core of last season's 14-18 team. South Carolina lost only Dwayne Day, who started a little over half their games. The biggest difference comes from Horn, who spent five years building Western Kentucky into a feared mid-major before heading down for what he called a program-building project in Columbia.
"I'm crazy. I thought we were going to be first last year," said Devan Downey, South Carolina's SEC player of the year candidate. "To finally do it — I'm not surprised. I knew it was coming all along. The only thing we had to do is correct a few things, play more together."
An August trip to Europe and a soft non-conference schedule let the Gamecocks learn Horn's high-speed, high-pressure philosophy on both ends of the floor and build confidence. The coach said everything seemed to come together on Jan. 2 when South Carolina battled back from 10 down twice in the second half on the road and beat Baylor on a layup by Zam Fredrick with 5.1 seconds to go.
"Late in that game there was a lot of talk and a lot of positive energy in huddles about what we needed to do and about how hard we had worked," Horn said.
South Carolina has also been helped with a little luck. The Gamecocks have won four games in the final 10 seconds and beat Arkansas in overtime. They beat Florida on Frederick layup after the Gators failed to seal the victory at the free throw line. A little over three weeks later against Alabama, Mike Holmes' winning tip-in at the buzzer may have still been on the rim, but it stood.
"We play with so much confidence. We never feel we're going to lose," said Downey, who has been the catalyst for this team, along with Fredrick, who were both high school stars in South Carolina and left the state for college before transferring back.
The team has bought into Horn's fast-paced philosophy. The Gamecocks have scored at least 73 points in SEC play nine times this season after making it past that mark just twice in 2008. They lead the SEC with 9.5 steals a game and force nearly six more turnovers than they commit.
South Carolina has just two players over 6-foot-8 on their 11-man roster — little used 6-10 junior Mitchell Carter and 6-9 sophomore Sam Muldrow. But that hasn't stopped the team from playing big. They set a school-record with 16 blocks in Wednesday's 77-59 win over Kentucky. Wildcats forward Patrick Patterson had eight of his shots blocked and missed 14 field goals despite almost every shot being inside five feet.
"Downey's terrific. I think everyone knows that," Arkansas coach John Pelphrey said after his team lost 82-78 in overtime last weekend. "South Carolina's success this year has come from their frontcourt's improvement."
The Gamecocks surprise success also has Columbia buzzing again.
South Carolina was a basketball powerhouse back in the early 1970s under Frank McGuire, going 14-0 in the Atlantic Coast Conference in 1970 and making four NCAA tournaments in a row. But the program foundered not long after the Gamecocks left the ACC. Their only other NCAA appearances came in 1989, 1997, 1998 and 2004, each time losing in the first round, once as a No. 2 seed and again as a No. 3 seed. They have won the SEC East just once, going 15-1 in 1997.
The team moved into its 18,000-seat arena six years ago, but the upper deck sat near-empty for almost every game. Nine of their 17 games last season were in front of announced crowds of less than 12,000 and many times they sounded a lot quieter.
Wednesday night, the Colonial Life Arena was full and loud, and Kentucky noticed.
"I heard the fans all night long. Whatever they were saying to me on offense and defense, whenever I scored, whenever I got my shot blocked, I could hear the crowd out there," Patterson said.
Dave Odom, who left South Carolina at the end of last season, followed Wednesday's game from Clemson, where he watched the Tigers lose to Virginia Tech. He said this year's Gamecocks were bound to improve with another year of experience.
"I couldn't be happier for these guys," Odom said.
The Gamecocks finish the season with Vanderbilt, Tennessee and Georgia, and Horn is reminding them not to pay attention to what's being said about them, just like he reminded them not to dwell on preseason predictions that had South Carolina finishing fifth in the SEC East.
"We've been doing that all year, whether it was beware people say you can't do it, or now beware they tell you that you're better than you are," Horn said.