From competitors to collaborators, Sens. Bob Menendez (N.J.) and Charles Schumer (N.Y.) have gradually warmed to each other as the new Democratic Senatorial Campaign Committee chairman has solidified his leadership standing and his predecessor has shifted his focus to legislating.

Schumer, who chaired the DSCC in the 2006 and 2008 cycles, hand-picked Menendez to succeed him. The move, while not necessarily surprising, was noteworthy given the two ambitious, bare-knuckle politicians who hail from the same region of the country have had their private scuffles. Yet those who know the Senators well say they have developed a healthy respect for one another and a solid working relationship in the upper ranks of the Democratic Conference.

“To say there is no tension between the two would be incorrect,— one senior Democratic Senate aide said. “I think they appreciate each other, but they are not best friends.—

With their close geographic proximity and the fact that the northern half of New Jersey is served by New York state’s largest media market, the Senators from the Garden and Empire states have historically competed for prominence and attention. Menendez and Schumer first clashed in 2006, when both men dueled for the attention of the television cameras and the political advantage in the controversy that erupted over President George W. Bush’s plan to let a Dubai company purchase the operations of domestic shipping ports.

But that same year, Schumer spent millions of dollars in DSCC money to help Menendez’s bid to retain the Senate seat he was appointed to by Gov. Jon Corzine (D). Corzine left the Senate after winning the governor’s chair in 2005, and, in turn, tapped Menendez to fill the last year of his term.

Menendez ended up in a hard-fought race to keep the seat in 2006, and Schumer’s help was not lost on the new Senator. For his part, Schumer came to recognize Menendez’s work ethic, doggedness and political smarts, attributes that led him to tap the New Jersey Democrat as his DSCC vice chairman for the 2008 cycle.

Now — with Menendez in the top DSCC post and Schumer focusing more pointedly on policy and legislative strategy as the Democratic Conference vice chairman — the two Senators’ relationship is once again evolving, and with it the dynamic of the Senate majority’s leadership team.

Aiding the transition has been Menendez’s decision to regularly consult with Schumer on DSCC business, Schumer’s willingness to relinquish his role as his Conference’s chief political adviser and Senate Majority Leader Harry Reid’s (D-Nev.) embrace of Menendez.

“When Bob took over, I said, It is your show. Any help you need from me, I will give you.’ And that’s what’s happened. We talk three or four times a week. He seeks my advice, he seeks my help, and we’re getting along great,— Schumer said Thursday. “Members always come to me and talk to me about their campaigns. But I always talk to Menendez, and vice versa.—

Menendez’s chief of staff, Danny O’Brien, said his boss views Schumer as an “invaluable resource,— adding that the two have a strong relationship.

Menendez actively sought to retain Schumer’s top DSCC strategists from the 2008 cycle and was successful in helping convince Executive Director J.B. Poersch and Political Director Martha McKenna to stay. Additionally, Communications Director Eric Schultz is a former Schumer staffer. He replaced Matthew Miller, who worked for Menendez before going to work under Schumer at the DSCC in 2007.

“A week does not go by without Sen. Menendez consulting Sen. Schumer,— O’Brien said.

As the newest member of the Senate Democratic leadership, Menendez is finding his footing after a first six months that brought with it some growing pains. Earlier this year, Menendez, a Cuban-American, and Reid clashed over a bill to loosen restrictions on Cuba.

Menendez was ultimately Reid’s pick to succeed Schumer at the DSCC, but their relationship doesn’t approach the close connection that the Majority Leader shares with the Conference vice chairman. Schumer and Reid were notorious for their constant phone chatter during Schumer’s two-cycle tenure as DSCC chairman.

Following the 2006 elections in which the Democrats won back the Senate majority, Reid went so far as to create a new leadership slot to thank Schumer for the victory. Menendez does not yet carry the same weight as Schumer did when he was DSCC chairman, nor does he have Reid’s ear in the same way, Democrats concede.

But a bond between Menendez and Reid appears to be taking root. The Majority Leader regularly includes Menendez in meetings that had previously included only the Democratic Conference’s top four leaders and Sen. Byron Dorgan (D-N.D.). Reid has even begun — albeit slowly — to consult with Menendez on electoral matters much in the same way he did with Schumer.

“Sen. Menendez has always been an aggressive, focused and committed Democrat, so it surprises no one that he has become such a strong leader in the short time he has been in his new role,— Reid said.

Individuals who have worked for both Menendez and Schumer say the two are similarly relentless in their want to win but employ different personal styles to achieve their goals. Menendez, who rose quickly in the House leadership ranks as well, is described as less of a micromanager than Schumer, but no less engaged or aggressive.

Some attribute any friction between the two to the Senate itself, where power is plentiful and egos are healthy. Still others chalk it up to the fact that Menendez took over a committee that for four years was personified by Schumer.

“They have different approaches in how they go about things, but they’re both stubborn that their approaches are the right way,— one senior Democratic Senate aide said.