For much of John Cornyn’s career,it was difficult to imagine him without also thinking of George W. Bush. Both moved up through the ranks of Texas Republican politics the same way: at the urging of Karl Rove, who pushed Bush toward his successful run for governor in 1994 and recruited Cornyn to resign his state Supreme Court seat to run for attorney general four years later.

The two became friendly during their time together in Austin. And two years after Bush won the presidency, Cornyn won his seat in the Senate — since then serving as one of the administration’s most loyal congressional foot soldiers. Last year, his White House fealty helped him secure the No. 5 job in the party hierarchy, vice chairman of the Senate GOP Conference.

But now Cornyn is starting to face a political future without Bush. By the time the president leaves Washington in January, Cornyn hopes to have secured a more prominent leadership role in a very different Senate GOP, one that has altogether shaken off its collective associations with the broadly unpopular 43rd president. But before that, Cornyn himself will be seeking to shake off his Bush connections just enough to secure re-election.

While he’s the clear-cut favorite at the moment, Cornyn faces a serious challenge from Rick Noriega, a Democratic state legislator from Houston for the past decade who served in Afghanistan in 2004 and 2005 as a lieutenant colonel in the Texas Army National Guard. Although Cornyn’s own approval ratings have been lackluster, he has an enormous advantage: 26 times as much money in the bank as Noriega in April, with new reports due July 15. Cornyn can probably also bank on Texas’ well-established preference for Republicans in statewide elections.

Winning a second term would be just the opening act in the re-positioning of Cornyn’s career. If he gets a new leadership job, perhaps as head of the party’s 2010 Senate campaigns, he’ll probably be called upon to distance his party from some elements of the Bush legacy — especially in fiscal matters, where many conservatives have charged that the Bush White House has fallen away from core conservative principles.

While the senator’s allies deny any suggestion that he has come to prominence thanks to his White House ties, there’s little doubt his Bush connections have smoothed his Senate path.

“Cornyn was looking for a way to make his name,” said Ross Ramsey, the editor of Texas Weekly, one of the state’s leading political publications. “Making your way in the United States Senate is a slow process. He jumped right into national prominence.”

It helped as well that Cornyn could tout his law-and-order background — six years as a trial court judge in San Antonio followed by six years on the state’s top civil appeals court — at the same moment the Bush White House was promoting a bevy of get-tough security measures to confront the global terrorist threat.

“He hit the ground in Washington saying, ‘I am a close friend of George W. Bush. I support the president,’ ” said Cal Jillson, a political science professor at Southern Methodist University in Dallas.

Cornyn’s voting record, too, showcases his affinities with the administration. Last year, he voted the way Bush wanted more than any other senator: 90.5 percent of the time. He also had the highest Senate presidential support score in 2005, and during his first four years in office his score averaged 96 percent.

Along the way, he has served as a vocal promoter of some of the most controversial White House priorities, including Bush’s most conservative judicial nominees, his assertions of broad executive power in treating suspected terrorists detained by the military and his efforts to expand the reach of his warrantless surveillance efforts. He stuck with fellow Texan Harriet Miers until her nomination to the Supreme Court foundered in 2005, continuously rebutting the chorus of conservatives who feared she would be too moderate.

Now his challenge is to develop a Senate reputation independent from the Bush era and its potentially damaging political legacy for the GOP. Of course, Cornyn puts things far more favorably for his party: He plans, he says, to work with other Republicans to promote a conservative agenda and win back the majority they held during his first four years in Washington.

Cornyn says that if he wins this November, he’ll look to hone and expand his domestic-policy portfolio, which until now has been largely focused on issues that come before him on the Judiciary Committee, by promoting Republican alternatives on issues such as energy and health care, as well as one of his signature issues, immigration.

Already he has begun, ever so prudently, to distance himself from Bush. He opposed the comprehensive immigration overhauls that came before the Senate in the past two years, both of which had strong White House backing, because the bills would have created a path to eventual U.S. citizenship for most illegal immigrants. Instead, Cornyn was the lead proponent of an alternative that would have required illegal immigrants to return home before they could apply to a temporary guest worker program. It also would have denied them any avenue to citizenship.

He has also broken with the White House on regulatory policy by sponsoring Senate legislation with Massachusetts Democrat Edward M. Kennedy that would grant the Food and Drug Administration the authority to regulate tobacco products, in part because the FDA would be better positioned, in Cornyn’s view, to rein in ads targeting at-risk teen smokers.

“He has values that match with the people of Texas,” said Nevada’s John Ensign, this year’s chairman of the National Republican Senatorial Committee (NRSC). Cornyn “shows enough independence,” Ensign said, adding that he “supports the president when he’s right, and he disagrees with him when he believes he’s wrong.”

In some ways, should he win this fall, Cornyn would be a natural fit to succeed Ensign at the helm of the Senate GOP campaign arm. Texas has long been a fertile hunting ground for Republican dollars, and Cornyn has been out in front of the soliciting pack. He hosted fundraisers in Dallas and Houston on June 9 that by his estimate garnered $300,000 for the open-seat GOP candidates in Colorado and New Mexico and for state Treasurer John Kennedy of Louisiana, the only challenger with a viable shot of taking a seat away from a Democratic incumbent.

“It’s really kind of premature to be talking about the next leadership elections,” Cornyn said. “But I want to do my part, because being in the majority is a whole lot more fun than being in the minority.”

Cornyn’s allies are somewhat less coy on the subject. Although the NRSC post is somewhat separate from the leadership hierarchy, it would provide him with a chance to boost his campaign bona fides and to curry favor among rank-and-file Republican senators. If they feel indebted — figuratively or otherwise — to Cornyn’s fundraising work in coming contests, he could plausibly turn that gratitude into votes for a top-tier leadership position. The current floor leader, Kentucky’s Mitch McConnell, chaired the campaign committee from 1997 through 2000; the previous floor leader, Tennessee’s Bill Frist, ran the campaign committee in 2001 and 2002.

“He’s on the leadership track,” said Minnesota’s Norm Coleman, a potential rival for the NRSC post if he wins his campaign for a second term in November, which now appears to be a tossup proposition. “So whatever he wants to do, the door’s open to him in the caucus. He’s very well respected.”

When he arrived in the Senate five years ago, Cornyn made a favorable early impression and quickly took on a de facto GOP leadership role on the Judiciary panel, a function in which he continues to serve.

“People are turning to him as a leader and as an expert, and I suspect that very few things are done on that committee without consultation with him, and that’s good,” said Orrin G. Hatch of Utah, a former chairman and now a senior GOP member of Judiciary.

After just a year in office, Cornyn was tapped to be deputy to McConnell, who was then party whip, setting the Texan on course to make a stronger case for the vice chairman post — a position usually reserved for more senior senators — less than three years later. At the start of this Congress, McConnell also recruited Cornyn to serve as the top Republican on the Ethics Committee, another familiar way station for future leaders. Both McConnell and Majority Leader Harry Reid of Nevada took turns on the panel before they were elevated to party leader.

Cornyn recently used the Ethics panel post to hammer on a predictably favorite theme for someone who majored in journalism in college: openness in government. In response to reports that at least two senators were given home mortgages on unusually favorable terms by Countrywide Financial Corp., Cornyn and Chairwoman Barbara Boxer, a California Democrat, corralled support among the other four members of the committee last month to require that senators include mortgage details in their annual financial disclosure statements.

Last year, Cornyn was central to the bipartisan effort to overhaul the Freedom of Information Act (FOIA) to speed public access to government documents. “People act differently if they know they are under public scrutiny,” Cornyn said, adding that he will continue to push for increased transparency about the process of earmarking bills with special projects and other measures to shine a light on government operations.

Such bipartisan efforts will probably continue to loom large, if all goes to plan and Cornyn wins a second term and the leadership profile he anticipates. In the next Congress, Cornyn would “concentrate on thickening the foundation under his status as an independent figure, as a senator from a big state that has to be dealt with on a number of issues,” said Jillson of SMU. “His earlier dependence on George W. Bush, and on Bush’s stature, will be gone.”

FOR FURTHER READING: Mortgage disclosure rules, CQ Weekly, p. 1771; tobacco regulation (S 625, HR 1108), p. 886; immigration overhaul, p. 50; 2006 Almanac, p. 14-3; FOIA rewrite (PL 110-175), p. 52.