Sen. Orrin Hatch (R-Utah) wants to make a deal.

An ardent conservative and one of the National Republican Senatorial Committee’s most prolific fundraisers, Hatch also is a Senate institutionalist who wants to use the friendships he’s forged with leading liberals over 33 years to stay relevant and get things done.

“I think he tries to do what he believes is the right thing. And so when he gets involved in an issue, if he believes that it’s right, he stands by that,” said Sen. John Ensign (Nev.), who tapped Hatch in the past cycle as his top lieutenant at the NRSC, of which he was then the chairman. “Some of the things in the past that he’s done with Ted Kennedy, it’s just sometimes he gets in it and he believes in it, and he stays with it.”

As President Barack Obama looks to build Republican support for big-ticket legislative initiatives such as a health care overhaul — as well as avoid a partisan meltdown over judicial nominations and a possible Supreme Court nominee — he will likely at least give Hatch a phone call to gauge his position.

Hatch was one of the first rank-and-file Republican Senators summoned to the White House for a meeting with the president just after Inauguration Day. However, Hatch’s penchant for deal-making has its limits: He is passionately opposed to Obama’s $787 billion economic stimulus bill.

“I really do try and work with some of my colleagues,” Hatch said. But he was quick to add: “They know if they really get me irritated and they get me mad, that I know how to shut this place down, and I’ve done it from time to time.”

Hatch’s close relationships with leading liberals such as Sen. Edward Kennedy (D-Mass.), combined with the respect he carries within the GOP Conference, leave him uniquely suited to operate at the center of complicated and potentially explosive negotiations over issues like health care and judicial nominations — two areas on which he has expertise.

One former Republican Senate leadership aide said Hatch is likely to be a key negotiator on several of the Senate’s upcoming legislative endeavors over the next two years. “He’s going to be a big deal; he’s pivotal,” this former aide said.

Despite strong conservative credentials on most social and fiscal matters, Hatch’s six Senate terms have been marked by his willingness to compromise with the likes of Obama, Senate Majority Whip Dick Durbin (Ill.), Sen. Patrick Leahy (Vt.) and Kennedy — hardly among the Democratic Party’s moderates.

As Obama faced trouble with top Cabinet appointees, including Treasury Secretary Timothy Geithner, Attorney General Eric Holder and former Sen. Tom Daschle (D-S.D.) — who ended up dropping his bid to become Health and Human Services secretary — it was Hatch who defended the president and his picks.

Holder faced early criticism for his role in several controversial Clinton-era pardons, while Geithner and Daschle were beleaguered by a failure to properly pay their taxes.

But Hatch argued publicly and vociferously for their confirmations. He lauded each nominee’s credentials and expressed a desire to reduce partisanship by, in his view, treating Obama better than Democrats treated former President George W. Bush.

Hatch’s close personal friendship with Kennedy is the stuff of old-school bipartisanship — they collaborated to pass the first State Children’s Health Insurance Program bill in 1997. And Leahy bragged that nearly every bill he has co-sponsored with the Utah Republican has passed.

“It’s an example of what happens when you have two grown-up Senators,” said Leahy, who is the Judiciary chairman but served as ranking member when Hatch then chaired the panel.

Kennedy has been largely absent from the Senate as he battles brain cancer. But upon request for this story, the veteran Massachusetts Democrat offered a statement about his relationship with Hatch: “Orrin and I don’t always agree, but we have a genuine friendship, and I have great respect for his ability. For much of the time he’s been here, we’ve been on the Judiciary Committee and Labor Committee together.

“Sometimes I’ve been the chairman, sometimes he’s been the chairman, but we’ve always managed to work together.”

All the while, Hatch has been able to collaborate across the aisle without alienating or frustrating his fellow Republicans, although GOP Senate aides acknowledge Hatch was asked politely to back off of endorsing Obama’s Cabinet nominees so publicly until their confirmation hearings were complete.

A Pittsburgh native and lawyer by trade until he was elected to the Senate in 1976, Hatch has maintained his good standing among Republicans by remaining solidly conservative on social issues and consistently against legislation that would grant labor unions more power, and serving as a vocal advocate for Bush’s judicial picks.

More recently, Hatch has garnered the respect of his Conference by becoming one of the few Senators other than the NRSC chairman to invest his time in raising money for the party and Republican Senate candidates. Sen. John Cornyn (Texas), the NRSC chairman this cycle, reappointed Hatch to serve as the committee’s vice chairman for exactly that reason.

Senior GOP Senate aides describe Hatch’s relationships with leading Democrats as “useful,” but say he continues to maintain his stature and credibility within the GOP Conference. “He’s relied on for fundraising and to go on national TV and represent Senate Republicans in a very positive light,” one aide said.

Hatch doesn’t mince words, and on issues ranging from abortion and marriage to fiscal and judicial matters, he is clearly not a moderate. Hatch is opposed to same-sex marriage — he has supported legislation to ban it — and he helped shepherd Supreme Court Justice Clarence Thomas through his controversial confirmation process.

Yet Hatch’s positions sometimes come as a surprise — he sides with Democrats and a handful of Republicans in supporting federal funding for stem-cell research, and he has led the charge to get the District of Columbia voting representation in the House. The latter would also give Utah, his home state, another seat in the chamber.

Hatch, a one-time amateur boxer, refers to Kennedy as having more sway than any other Senate Democrat with “the unions, the trial lawyers, the gays and lesbians, the environmentalists and the feminist groups.” But that is exactly why Hatch, with his affinity for compromise and desire to stay engaged, has been drawn to Kennedy over the years, aside from their friendship.

“He can put more people together for a project than almost anybody,” Hatch said. “Plus, as liberal as he seems to be, he is open to good ideas. And he is open to working with people like me who in good faith have worked with him in the past.

“When it comes to principle you don’t budge. I don’t budge at all,” Hatch continued. “But when it comes to getting things done, I have to recognize there are 535 people in [Congress] that you’ve got to work with.”