Sen. Chuck Schumer of New York is exceptionally smart, a prodigious worker with keen political instincts who sometimes can be a bit of a bully. The perfect Democrat, it would seem, to lead the opposition against President Donald Trump.

That is, if he curbs his penchant to be transactional and is tough and skillful enough to hold together a diverse Senate caucus.

The 66-year-old New Yorker, a lifetime politician, is taking over from Senate Democratic leader Harry Reid, who is retiring. Schumer is achieving a long-held ambition, though he wanted to be majority leader. Still, with 48 members and the reality that it usually takes 60 votes for legislation to clear the Senate, Schumer may be the most important Democrat in Washington.

He probably won't exactly emulate the approach taken eight years ago by his Republican counterpart, Senator Mitch McConnell, who quietly tried to thwart the new president at every step and in every way.

A progressive pragmatist, Schumer needs to protect the several dozen Democratic incumbents up for re-election in 2018; these include 10 from states Trump carried, such as West Virginia's Joe Manchin and Heidi Heitkamp of North Dakota. That may make it more likely that Democrats will cut deals with Republicans, which Schumer has done frequently in the past.

Such arrangements, with the possible exception of infrastructure spending, would be opposed by the Democratic caucus' influential left wing, led by Massachusetts Sen. Elizabeth Warren and Vermont's Bernie Sanders. Schumer can ill afford to alienate these lawmakers. (He enjoys a good personal relationship with Sanders; they went to the same Brooklyn high school.)

Some liberals already are raising red flags about their leader's penchant for cutting deals. They worry he lacks the toughness of Reid and the core principles of an effective predecessor, George Mitchell. Moreover, Schumer has never been a disciple of the famous dictum, sometimes attributed to President Harry Truman: "It is amazing what you can accomplish if you do not care who gets the credit." Schumer loves the limelight.

Yet he already has reached out to colleagues far more than Reid did. Like the former illustrious Senate Republican leader Howard Baker, Schumer promises to enlist his Senate colleagues, dole out more responsibilities. He has assembled a leadership team of more than a quarter of his caucus, including Warren and Manchin.

Associates say Trump's actions and appointments during the transition have caused Schumer to feel less accommodating. The right-wing tilt of the Trump Cabinet, exemplified by as the recent decision to name Rep. Mick Mulvaney of South Carolina, a tea party favorite, to be director of the Office of Management and Budget, has reinforced the notion that Senate Democrats will be in perpetual conflict with Trump administration.

This is apparent in the recent rhetoric of the two New York deal-makers. In his first speech as Democratic leader last week, Schumer charged Trump had "forgotten" his campaign pledges, that his cabinet was "staffed with billionaires, corporate executives, titans of Wall Street and those deeply embedded in Washington's corridors of power."

Trump shot back, calling Schumer a "clown." Some Republicans speculate that the president-elect thinks he can muscle Schumer. That's a miscalculation.

The Democratic leader has laid down a tough marker for the confirmation process, which may be more protracted than Republicans planned. He's likely to produce a united party front against some of the more controversial nominees.

More important, he hopes to keep Democrats together in opposing any repeal of Obamacare without a replacement. And to resist the strategy of forcing Democrats to work with Republicans on a replacement.

To bolster Red State Democrats, the progressive Center for American Progress commissioned a poll of 14 states where Democrats face re-election next year, three-quarters of them carried by Trump. The survey, conducted by Hart Research, found that a majority of these voters want Democrats to be a check on the new administration and to oppose repealing Obamacare before there is a specific plan to replace it.

Schumer, who lives and breathes politics, will use this and other data. He is relentless. During May commencement season in New York he'll pop into dozens of college, and some high school, graduations to give a short pep talk and then take off for the next one.

One his favorite stories is about he graduated from Harvard and was offered a Fulbright scholarship and at the same time fell in love. Explaining his dilemma, he recounts the balancing act: "Fulbright ... Girl ... Girl ... Fulbright." In a decision that would surprise his contemporaries, he chose romance. Then she dumped him.

The moral to those graduates is that they too can face setbacks and go on to do great things like the senator. He may want to recount that story to the party he leads which has been dumped by the voters.