Sen. John Cornyn (Texas), the GOP Conference vice chairman, is now in the mix of possible candidates to head up the National Republican Senatorial Committee next cycle, several senior Republican sources have confirmed.

Cornyn — the No. 5 ranking Republican — joins two other possible contenders for the Senate’s top campaign job in 2010. Sens. Norm Coleman (Minn.) and Bob Corker (Tenn.) also have been mentioned as possible successors to NRSC Chairman John Ensign (Nev.), who has all but ruled out another two-year stint at the demanding post.

Several Republican sources confirmed last week that Cornyn has “been approached” by his fellow leaders to consider switching leadership jobs in January. The NRSC position, they argue, would provide Cornyn — a prolific fundraiser and an ambitious up-and-comer — the chance to raise his profile as he awaits another opportunity to move up the Senate ranks.

“It’s definitely being talked about,” acknowledged one senior Senate Republican aide, speaking on the condition of anonymity.

Brian Walsh, Cornyn’s spokesman, said his boss has only one future race in mind — his 2008 re-election to a second term. “Sen. Cornyn is focused on serving his Texas constituents and advancing a positive, reform agenda in this Congress,” Walsh said.

“It would be far too presumptuous to think beyond this year when Sen. Cornyn is up for re-election himself this November,” he added. “He is doing everything possible to support Sen. Ensign in the effort to regain a Republican majority this year and not two years from now.”

Until now, most Republicans believed Cornyn would remain as Conference vice chairman at least through the 111th Congress. The most likely scenario has been for Cornyn to ultimately follow the footsteps of his Texas colleague, Sen. Kay Bailey Hutchison, who, as chairwoman of the Republican Policy Committee, is the No. 4 ranking Republican.

Hutchison has said she will not seek another term in 2012 and is a likely gubernatorial candidate in 2010 — a move that could free up the policy job for Cornyn before the end of her current term. Cornyn will not challenge his home-state colleague for a leadership position, nor would he leap over her to run for a higher post.

A high-level Senate Republican said if Cornyn were to make a run for the NRSC next cycle, it wouldn’t come as a surprise since he has few opportunities to climb the GOP ladder in the near term. That post would give him greater visibility nationally and also allow him to flex his political muscles in what many believe will be a far better election cycle than 2008.

“John is very interested in advancing in leadership, and he feels trapped by [Hutchison] right now,” the Republican said. “He can’t leapfrog over her. As long as she’s there, it’s an uncomfortable position for him. Vice chair gets him a seat at the table, but there’s not a whole lot of independence there.

“And he’s made as much out of it as anybody.”

Another senior Republican aide — although acknowledging no direct knowledge of Cornyn’s interest in the NRSC — said the Texas Republican would succeed if he sought the position.

“He’d do a hell of a job,” said the aide. “He’s from a big state. He can raise a lot of money. He’ll be recently re-elected and safe for another six years.”

The scenario would lead to an interesting shakeup of the lower tier of the GOP leadership. Cornyn would open up his vice chairmanship, which Ensign is likely to consider. The junior Nevada Senator had been a contender for that post two years ago before agreeing — under pressure from Minority Leader Mitch McConnell (Ky.) — to chair the NRSC.

The campaign committee might turn out to be one of the more highly sought after positions next cycle — as opposed to this year when McConnell struggled to enlist a taker. Ensign took it over after Sen. John Thune (R-S.D.) decided the job would interfere with his family life.

Like Coleman, Cornyn must first win re-election this November before deciding his next move. But Cornyn — with $9 million in the bank and no strong opponent — faces an easier road ahead than does Coleman, who, while leading in most polls, is viewed as one of the Democrats’ top targets with challenger and comedian Al Franken taking him on this fall.

Coleman has publicly dismissed talk of wanting the NRSC job, saying as recently as last month that he is “so focused on his re-election” that he cannot even entertain the idea. But privately, many Republicans say Coleman’s interest is strong, especially since he ran for it in 2006 and lost by just one vote to Sen. Elizabeth Dole (R-N.C.).

Plus, Coleman has been putting out the signals that he’s ripe for a new challenge — even while he’s facing re-election. He has given money through his political action committee to most of his colleagues this cycle.

Asked about his Northstar PAC giving this year, Coleman said: “I am here to get something done. First, I have to make sure I get back here, and second, I am focused on making sure my colleagues get back here to do good things.”

Corker, a freshman just rounding out his first Congress, is more of a long shot for the NRSC in 2010. But he’s viewed as one of the Conference’s rising stars and in just the past six months not only assembled a leadership PAC but also has started giving to most of his in-cycle Senate colleagues.

Corker insisted that his interests have nothing to do with leadership goals — rather he’s simply trying to repay the generosity his colleagues showed him when he ran for the Senate in 2006. Corker said his interests lie in making his first term a success by honing his policy skills and delving into “major complex legislation.”

“What I want to do now and through 2012 is be a great Senator,” Corker said. “I want to help shape the direction of the country.”

While both Corker and Coleman are more independent-minded, Cornyn is one of the Senate’s more conservative Members. Those political leanings could prove to be a key factor for Senators in choosing their next NRSC chairman, since 2010 is likely to continue a transition period for the GOP.

“They’d all be good,” observed one Republican Senate aide. “They all have strengths. I don’t think anybody would be bad — that’s the positive side of it.”

At the same time, the two-year cycle should provide a better landscape than 2008 where Ensign is looking to defend 23 Republican-held seats against the Democrats’ 12. 2010 puts 19 GOP incumbents in play versus the Democrats’ 15.

Those numbers notwithstanding, the political landscape likely will be far superior for the GOP than this one.

Even if a Democrat wins the White House this fall, the Republicans will have historical trends playing to their favor. Similarly, a new GOP president would give the party new appeal and a new face after eight years of an increasingly unpopular President Bush.

“Next time will be better,” said the senior Republican aide. “It won’t be worse than this time.”