WASHINGTON - Sen. Charles Schumer, arguably New York's most outspoken politician, has publicly pledged not to take sides as Caroline Kennedy and others seek appointment to the U.S. Senate. It's an unusual stance for the man who has picked or backed Senate candidates in every other state in the union.

Schumer recently relinquished his role as head of the Democratic Senatorial Campaign Committee, where he spent the past two elections hand-picking some candidates, and strategizing with others on how to win. Even his critics concede he was masterful at guiding Senate campaigns, helping the Democrats go from a minority party to a strong, nearly filibuster-proof majority.

Yet when it comes to picking someone in his backyard - and his future partner in the Senate - he insists he has no favorite as Gov. David Paterson prepares to name a successor to Hillary Rodham Clinton, should she be confirmed as secretary of state.

“Each one of them would make an excellent senator,” Schumer said this month, declaring he would not back any individual for the job.

Steven Cohen, a professor at Columbia University, said a lot can be learned from Schumer's record of picking candidates in other states, and his personal connections to a key Kennedy adviser.

“From his perspective, she's the ideal candidate,” Cohen said.

A close ally of Schumer's, Senate Majority Leader Harry Reid, called Kennedy “perfect” for the job, but Cohen said a better indicator of Schumer's mood is Kennedy's hiring of Josh Isay, a former Schumer chief of staff, to run her bid for the seat.

“If Schumer was against her, he wouldn't have taken that job,” said Cohen.

For New York's senior senator, Cohen said, “this is the kind of situation where if you signal what you'd really like clearly, it might get you into trouble. This is Schumer's home state, and so he will have to tread a little more carefully here than in other places, because it affects his own political situation, his own re-election.”

Schumer spokesman Josh Vlasto declined to comment.

Money is where Kennedy can help - or at least not hurt - Schumer the most. Presumably, she can raise large sums for the 2010 campaign, when she would have to run for the seat at the same time as expensive re-election bids by both Paterson and Schumer.

Schumer is not expected to have a tough time winning another term, but that doesn't mean he wants it to be any harder than it has to be.

Others believe that by staying out of the internecine fight, Schumer is following a long political tradition.

“Classically, U.S. Senators disengage,” said Gerald Benjamin, professor of politics at SUNY New Paltz. “The ones that have been engaged in state politics have been exceptional, like Al D'Amato, and the reason is as long as nobody threatens his or her base they want to deliver from Washington and not anger any faction that might cause them trouble or a primary.”

In the early handicapping of the Senate seat scramble, some political observers suggested Schumer would dislike having Kennedy join him in the Senate, because she would steal some of the spotlight, much as Clinton did.

The record seems to disprove that.

As he worked alongside Clinton over the past eight years, Schumer became one of the most powerful senators in the country, so it's unlikely he worries much over the arrival of a political neophyte like Kennedy, who might well need Schumer's help with legislative maneuvering and home state politics.

There are plenty of people to offend, should Schumer take sides in the Senate seat battle. First, there are all the other candidates vying for the job: Kennedy, New York Attorney General Andrew Cuomo, Nassau County Executive Tom Suozzi, Buffalo Mayor Byron Brown, and Reps. Carolyn Maloney, Steve Israel, Jerrold Nadler, Kirsten Gillibrand, and Brian Higgins.

Paterson's decision is likely still weeks away.

Assuming Clinton is confirmed as President-elect Barack Obama's secretary of state, whoever the governor picks to succeed her will hold the seat for two years, have to run for election in 2010 and, if successful, run again in 2012.

If Schumer manages to publicly stay out of the fray while Paterson decides, it will not be the first time the voluble senator has taken a pass on the most pressing political issue in the state.

Last year, he steadfastly refused to take a stand on then-Gov. Eliot Spitzer's plan to issue driver's licenses to illegal immigrants, saying it was a state issue, not a federal concern, even after Spitzer tried to salvage his plan by cutting a side deal with federal homeland security officials.

Even as Schumer shied away from that fight, Gillibrand, a freshman congresswoman, came out against it in a decision that carried major risks whichever way she went.

Back then - and now - Schumer is betting on silence.