When Senate Minority Whip Trent Lott (R-Miss.) resigned his seat late last year, he did more than simply hand over the keys to his leadership office to his friend and ally, Sen. Jon Kyl (R-Ariz.). The veteran lawmaker left Kyl with some advice: Build on his House relationships to continue his informal role as the Senate’s chief emissary to the other body.

For years, Lott took it upon himself to be unofficial envoy between the Senate and House GOP, regularly working his relationships with phone calls, at private Member functions and on the House floor during lengthy votes. A former House leader and rank-and-filer, Lott believed that the best way to strengthen his party’s hand was through its relationships, coordination and unity.

“One of the things I encouraged Jon to do is spend time over there,” Lott said in an interview this week.

Although a number of Senate Republicans with roots in the House are regular visitors to the chamber, none has positioned himself as an heir to Lott as the unofficial GOP Senate ambassador, and Kyl appears to be the likely successor.

Kyl also began his Congressional career in the House, where he worked alongside and even within Lott’s House Whip operation. So, Lott said, it made sense for Kyl to try to do some of the same liaison work that he did, such as attending the Wednesday evening House GOP “Chowder and Marching” events and spending time with Members to cement a link between two chambers that often operate in isolation.

“House people in both parties tend to get uptight about the Senate — they feel the Senate doesn’t appreciate them,” Lott said. “I think they always viewed me as a House guy who moved over to the other side.”

Kyl didn’t want to discuss specifics about what he’s done in the past two months to fill the void that Lott left, saying only that he’s engaged in “a number of informal activities” to improve ties with his House colleagues. Kyl said Lott was “absolutely right about the importance of maintaining good contacts.”

“Trent was able to keep up his old House contacts very well, and it served him well as the Whip, and it served our Conference well,” Kyl said. “I’ve certainly tried to do the same thing in taking on the role of Whip.”

Yet the more cerebral Kyl said he’s under no illusions that his style and strengths parallel Lott’s, whose affability, personality and political instincts were distinctively his own. Kyl acknowledged that he hasn’t “done it exactly the same as Lott” but that he — along with other members of the GOP leadership — are working to enhance intraparty cooperation in Lott’s absence.

“Trent is an extraordinary person with unique skills,” Kyl said. “You have to go with people’s strengths. You end up doing what you do best and make sure we work well as a team.”

House Republicans said that while Kyl has begun to take steps toward building similar relationships, it is unlikely that he can duplicate Lott. “I don’t mean to say anything bad about Jon Kyl, but he just doesn’t have the personality of Trent Lott,” one House GOP leadership aide said, explaining that Lott’s ability to work with House Members was based in his friendships.

One of the most famous examples of his ability to reach a broad range of Members is his recruitment of former Rep. Tom DeLay (R-Texas) and then-Rep. Olympia Snowe (R-Maine) into his Whip operations. Although DeLay, the quintessential conservative firebrand, and the moderate Snowe would appear to have little in common, Lott not only worked closely with them but also ultimately brought the two together as friends and colleagues.

Even during Lott’s fall from grace following his comments about former Sen. Strom Thurmond (R-S.C.), Lott continued to use those relationships and his ability to work with the House behind the scenes. Former Senate Majority Leader Bill Frist (R-Tenn.) — who replaced Lott and had a famously cool relationship with him — often used him as an unofficial ambassador to the House and to help cut deals with recalcitrant House Members.

Because he was able to cross the building and easily chat up rank-and-file Republicans as well as House leaders, Lott helped broker deals on a variety of bills, including energy legislation and the massive transportation reauthorization bill.

Nevertheless, Republicans said, Kyl has done a good job in reaching out to the House over the last few months. Sen. Richard Burr (R-N.C.), who regularly lunches with his one-time House colleagues, said Kyl is picking up where Lott left off: He’s established a close relationship with House Minority Leader John Boehner (R-Ohio) and has increased his informal outreach. As Burr put it: “You don’t have House Members back-channeling messages to the Senate — it seems to be pretty smooth.”

Lott’s position as the GOP liaison seems somewhat of a rarity in Congress. No Democrat has taken on that role, although for years then-Minority Whip Dick Durbin (D-Ill.) was the next-best thing as he sometimes attended House Democratic Caucus events, regularly met with House leaders and rank and file, and worked that chamber’s halls.

Like Lott, Durbin is well-liked by his Senate colleagues, and as one former House Democratic leadership aide said, is considered the most “down to earth” Senator by many of his House counterparts.

According to Durbin aides, Durbin has continued to make the short trek across the Capitol since becoming Majority Whip last year. But the expanded duties that come with the job — as well as being one of Sen. Barack Obama’s (D-Ill.) top boosters — have limited the time Durbin can spend with House lawmakers. Although he continues to help broker bicameral messaging events and legislative efforts, the time he has to work the House floor has become significantly limited.

And beginning in the last few years of their time in the minority, then-leaders Nancy Pelosi (D-Calif.) and Harry Reid (D-Nev.) began increasing their time together, holding regular meetings between the broader leadership team. That practice, which continues, led to the duo forming an intraparty message and platform for the 2006 election that dovetailed with the Democrats’ return to power.

Sen. John Thune (R-S.D.), a former House lawmaker who has worked as Chief Deputy Whip under Lott and now Kyl, said it’s critical that Republican Senators continue Lott’s legacy as the ambassador. Like Kyl and Thune, there are several House Members turned Senators who could revive that link.

“Discussions between the House and Senate leadership is really important,” Thune said. “A lot of that happens in an evolving way and we’ve got a lot of people in leadership with prior House experience to do that. It’s important we be on somewhat of the same page. It was something Trent paid particular attention to, and others are going to have to step up.”

Like the House and Senate Democrats, Congressional Republicans hold across-the-Dome Member and leadership meetings, and regularly discuss message and strategy. But GOP sources in both chambers say those bicameral meetings aren’t necessarily on a set calendar — a reality that could become increasingly problematic for a party out of power.

“Next year, given the possibility there will be even fewer Republicans in both chambers, we have to be more united than ever if we are going to impact legislation,” said a senior Senate Republican aide. “That’s when someone with strong emissary skills will be critical.”