As he settles into a high-backed chair in his private Senate office, John Thune tells me that if he jumps into the 2012 presidential race, he will be in it to win it — no test-run for 2016, no show-horse spectacle. “The reason you do it is that you really believe that the future is now,” he says. “I believe that.”

For months, the South Dakota Republican has been on the fence, weighing the pros and cons of a White House bid. Now, in the ides of February, the 50-year-old father of two is in the “final stages” of the decision-making process. “It is a gut-level decision,” he says. “We are getting closer to making it.”

As Thune eyes President Obama’s continued push to increase the size and power of government, he hints that the “damage” the administration could inflict in a second term is “motivation enough” for anyone looking to mount a challenge.

Over the weekend, Thune gave a crackling speech to the Conservative Political Action Conference in Washington. Although he finished in the lower tier of the event’s straw poll, he did stir activists to pay attention to a fresh face. He spoke movingly about his family’s immigrant history and his Midwestern values. He also poked a little fun at his own comparative anonymity on the national stage.

“It’s fair to say that I don’t have the same national name recognition as some of my more famous Republican colleagues,” Thune mused. “I’ve never had a book signing. I’ve been to Iowa plenty of times, but it’s usually on the way to South Dakota. And the closest I’ve come to being on a reality TV show is C-SPAN’s live coverage of the Senate floor.”

Thune knows that a presidential bid would be an uphill climb for a little-known senator. Yet he sees ample opportunity next year for a new GOP voice to emerge — and to win. As he put it at CPAC, “I’m betting that 2012 is going to be the year when we not only take back the Senate, but also the White House.”

The tall, rail-thin senator, who starred on the basketball court at Murdo High School, likes to frame the upcoming contest in sports terms. “If I run, I would be on offense,” he says with a grin. “I am not afraid of a fight. If I get into this, it’s something I get into with all of my heart.”

“As Republican voters think about who they want to nominate, it really ought to come down to which candidate can defeat President Obama,” he says. “It really comes down to match-ups. Sometimes you have a very talented group of athletes. But at the end of the day, it comes down to who matches up best against your opponent.

“That’s the reason the Lakers have a hard time against the Celtics,” Thune chuckles. “They have a hard time guarding certain people; they have a hard time guarding Kevin Garnett. There are simply teams that match up better against other teams.” Voters, he predicts, are going to have to play strategist, coalescing around the “most conservative, most electable” candidate.

As he surveys the field, Thune sees many familiar names, many leaders he admires. “It will be a challenge for any candidate this year, with the crowded field on the Republican side, for someone to break out,” he admits. “So how you differentiate yourself, how you define yourself, in early states in particular, will be important.” Thune, for his part, has not traveled much to Iowa and New Hampshire in the past year, mostly because he does not like to generate endless buzz.

Thune thinks he would present a “great contrast” to Obama in terms of political philosophy. He also believes that in terms of temperament and drive, he would stack up nicely against his fellow hoops-loving (former) Midwestern senator. “When it comes to age and energy, all those sorts of things, I think it could be a great match-up.”