As the mastermind behind his party’s takeover of the Senate in 2006, Sen. Charles Schumer (D-N.Y.) has seen his stock skyrocket in recent months among his Democratic colleagues.

But even more importantly, Schumer has won himself critical influence with Majority Leader Harry Reid (D-Nev.), and Senators in both parties say the brazen New Yorker’s stamp can be witnessed on most every move the new majority makes these days.

“In my opinion, his influence is supreme,” offered Sen. John Cornyn (Texas), one of Schumer’s top Republican rivals. “He’s everywhere.”

Now in his second tour as the chairman of the Democratic Senatorial Campaign Committee after wrenching six seats from the GOP in 2006, Schumer also has won himself an official place at Reid’s elite leadership table as the Caucus vice chairman.

Reid created that No. 3 slot specifically for Schumer late last year — an overt tip of the hat to the man who delivered him control of the Senate in November. Reid also gave Schumer the gavel at the obscure Joint Economic Committee, an added bonus to the seat Reid previously handed Schumer on the powerful Finance Committee as a reward for agreeing to take on the DSCC the first time.

“There’s been significant growth in [Schumer’s] strength,” said Sen. Frank Lautenberg (D-N.J.). “From his encouragement of qualified people to run, raising money at an unprecedented rate and being able to tell the Democratic story so forcefully and with believability, his personal esteem has continued to grow.

“And as a consequence, his leadership quality burst forward and he and Harry Reid struck an alliance. I would call it a perfect merger.”

“He’s definitely a player,” added a senior Democratic Senate aide. “From where he was on Election Day 2004 to where he is now, he’s had a net gain of influence more than any other Member of the Democratic Caucus.”

An Odd Couple

Schumer’s committee and leadership positions by themselves could have given him a direct line to Reid’s ear. But Democrats almost universally say Schumer’s relationship with Reid solidified long before the successful 2006 election — dating back to when Schumer first agreed to take on the grueling job of top political fundraiser and strategist at the DSCC in late 2004.

“We worked hand-in-glove,” Reid said. “No one thought we could do it except him and me.”

“We went through the experience of the 2006 election,” Schumer added. “It was kind of like being in a foxhole together.”

Schumer has over the course of the past two and a half years eased into the role as the Democratic Caucus’ leading political adviser — helping to chart strategy and formulate policy that seeks to advance the new majority’s standing with the electorate.

Schumer’s not only seated at every leadership meeting with Reid, Majority Whip Dick Durbin (Ill.) and Caucus Secretary Patty Murray (Wash.), but he and Reid are in near-constant contact, speaking by phone up to a dozen times a day.

“Let’s put it this way, on my speed dial I have my family, my top staff people, my two best friends and Harry Reid,” Schumer said.

“They are as close as close can be,” noted Sen. Bob Menendez (D-N.J.). “On politics, on fundraising, on any given policy, there’s no question Reid listens a great deal to what Schumer has to say. He’s not always going to do what he tells him, but Harry Reid appreciates what Chuck has to say.”

But while that may be the case, neither Schumer nor Reid accepts the suggestion that Schumer commands unique sway with the Majority Leader beyond the other two Democratic leaders, each of whom has a particular role to play.

“I work hard at this,” Schumer said. “I have no illusions that if we didn’t have a great team we couldn’t accomplish what we’ve been able to accomplish.”

Reid said Schumer’s attributes are aplenty, and understandably “he has more stature [with the Caucus] than when he started last cycle because we had nothing to show for it.” But Reid also asserted that each Member of his leadership team offers strengths and weaknesses, and that the Durbin/Murray/Schumer trio — not one individual — “helps me make every decision I make.”

Democratic Senators and sources describe the private interaction between Schumer and Reid as at times brotherly and at others antagonistic. They are very direct with one another, and as one knowledgeable Democratic source said, Schumer may be the only Senator “who can get away with interrupting Reid.”

On the other hand, Reid has made sport of regularly and sometimes ribbed Schumer publicly, largely over the extrovert New Yorker’s penchant for pursuing media attention through numerous press conferences, interviews and gaggles.

As Sen. Ben Nelson (D-Neb.) said of Schumer: “He’s well-respected, well-liked and well-teased.”

With a relationship that first began more than two decades to when they both served in the House, Schumer and Reid always have had more differences than similarities. Schumer is attracted to the spotlight, assertive and at times even brash; while Reid is a quiet, reserved student of the Senate who often basks in his own obscurity. Schumer rarely sleeps, while Reid is early to bed and early to rise.

Reid has even had to instruct Schumer — known as much for his love of his cell phone as for his affinity for the camera — to stop calling after 10 p.m.

Yet the two alter egos share a keen interest in politics, and most Senate Democrats say the duo has struck the right balance in a diverse Caucus. Senators note that Schumer adds the essential political element to what is Reid’s strong suit — harnessing Senate rules and procedures to execute the party platform.

“Schumer is the political animal in their Caucus,” observed Sen. John Thune (R-S.D.). “It appears a lot of the decision making is influenced by the political advice he gives. His focus is exclusively on how to grow their majority in 2008.”

“He brings in a lot of perspective on the races around the country that helps us to formulate our positions,” Durbin said.

In fact, Democratic and Republican Senators alike say Schumer’s contributions to the new majority are far from inconspicuous. As Sen. Byron Dorgan (D-N.D.) put it: “The proof is in the pudding.”

Setting the Agenda

While Schumer isn’t the only Senator to whom Reid listens, Democrats acknowledge he’s had a hand in the party’s move to hold numerous Senate votes on the Iraq War — an issue the party believes may be their political ace in the hole again in 2008.

More obviously, Schumer is the driving force behind the Democrats’ ongoing offensive against embattled Attorney General Alberto Gonzales over the firing of nine U.S. attorneys.

The latter may be the starkest example so far of Schumer’s stamp since the Democrats took charge in January. The veteran lawmaker not only spearheaded the Judiciary Committee’s investigation into the federal prosecutors’ ousters, but Schumer also was the architect of the plan — advanced by Reid — to force the Senate to consider a vote of no confidence two weeks ago against the attorney general.

Behind the scenes, Democratic sources say Schumer remained insistent that the leadership push the Gonzales vote forward, even as accusations abounded from the right that Schumer was unfit to lead an inquiry into the scandal as the chairman of political fundraising arm, the DSCC.

Those charges even gave pause to some Senate Democrats, party sources said, as they feared GOP counterattacks questioning their credibility and calling for separate confidence votes against the majority party’s leadership.

Helping lead the offensive against Schumer, Minority Leader Mitch McConnell (R-Ky.) took to the Senate floor to urge him to step aside from the investigation, saying: “I hope it is not the case that our friend from New York wrote this resolution and pushed the Senate to spend its valuable time on the particular position for partisan political purposes.”

And even some in Schumer’s own Caucus were none too pleased with the move.

Though he said it “was nothing personal,” Sen. Joe Lieberman (ID-Conn.) was the only Caucus member to oppose Schumer’s resolution, saying recently “if we want the public to respect what we’re doing here and how we’re doing it, we shouldn’t do [those] things.”

“It was clear that spending time on the Gonzales no confidence vote was not going to have any effect,” Lieberman said. “It was wasted time.”

Notably, it was Reid who was the loudest defender of his New York colleague, delivering an impassioned floor speech that some observers said underscores the intensity of the two Senators’ partnership.

“I work very closely with this man … any suggestions that were made to impugn his integrity are unwarranted, out of line and unfair,” Reid said at the time.

Reid acknowledged that Schumer can at times be overly aggressive, but when that occurs, the veteran Nevada Democrat said “we just tell him and that’s it.”

“He’s very calculated in what he does,” Reid said. “He rarely makes a mistake.”

A Target for Critics

Perhaps that’s why Schumer is often one of the Republicans’ favorite villains, and the Gonzales debate was just the latest in a series of examples where the two-term Democrat has come under attack from the right.

During last spring’s debate on a lobbying and ethics measure, for instance, it was Schumer who successfully ambushed the then-majority Republicans with an amendment to block Dubai Ports World from managing operations at several U.S. ports. The move set off a firestorm of GOP criticism and procedural wrangling to try to block the New York Democrat from getting a vote.

Schumer’s move particularly riled Republicans who believed he had gone back on his word after having pledged — along with a bipartisan group of nine other Senators — to wait until a 45-day security review was complete before demanding a vote on the deal.

Indeed, Schumer’s critics have become quite adept at lobbing charges at a colleague for whom they acknowledge they share both disdain and admiration. Cornyn said that while he believes Schumer is “singularly focused on the next election,” he has “nothing but respect for his political skills and his intellect.”

“I think the Republicans think I am a worthy adversary,” Schumer offered. “You know we took back the Senate and they didn’t like that.”

Emily Pierce contributed to this report.