Rahm Emanuel is a legend in Washington politics. In many ways he reminds me of the late Lee Atwater, another legendary Washington political operator who was a Republican kingmaker in the 1980s. But here is a key difference between Emanuel and Atwater. Atwater never held elected office.

Atwater was a winning presidential campaign strategist and Republican party leader. He was a master dealmaker, a political operative of the highest order. But he knew his limits. He was never the candidate because his love of life, humor and irony stopped him from pretending to care about politics and kissing babies. It just wasn’t him. He was a master dealermaker, a political operative of the highest order who was not above the dirtiest of low ball politics. Atwater once announced that he planned to defeat Democrat Michael Dukakis in the 88 presidential race by stripping “the bark off the little bastard.”

On Friday, President Obama announced that Emanuel was stepping down as his chief of staff. Emanuel was emotional in his farewell speech at the White House. The president's now former chief of state has decided to leave his post to run for mayor of Chicago. In that new role he is going to have learn his limits or prove capable of radically expanding his skill set. The closest that Emanuel has come to running for mayor of a big city is running and winning a seat in Congress. But there is a big difference between a congressman and a mayor. The mayor of Chicago has more constituents than most members of Congress. The mayor’s face is a daily fixture on tabloid front pages in matters ranging from clearing streets after snow storms to handling anger over a police shooting.

A congressman from a safe seat, like a White House chief of staff or a party chair, speaks from a position of distant authority and power. A mayor is in your face and every union leader, alderman, community activist and minister is in the mayor’s face. A mayor better have charm, patience and a terrific sense of humor to deal with his political reality.

And that is where Emanuel’s skill set comes up short – no joke intended about his height.

The best of Emanuel’s skills set is his ability at intimidation, pressure tactics and being dismissive. They all have their place in politics. Emanuel famously sent a stinking, dead fish to pollsters who delivered bad news and used a knife to publicly symbolize killing his political opponents. He had no trouble talking down to his higher ups, such as when he told British Leader Tony Blair before a speech in support of Bill Clinton -- “Don’t f... this up!” It is accepted insider wisdom in Washington that the wild-eyed, sharp elbowed character Josh Lyman in the West Wing was based on the manic behavior of Emanuel.

Being feared has its advantages in politics, both national and local. That is why Emanuel has thrived.

But even the toughest of mayors, such as Chicago’s original Mayor Daley, knows how to march in a silly parade and glad-hand ranting bag ladies to win their eternal loyalty. New York’s Michael Bloomberg knows how to make peace with controversial figures like Al Sharpton as well as weather controversies over building a mosque near Ground Zero.

Once elected, the mayor has to answer to demanding voters, pesky journalists and insolent block captains. And before the election the candidate for mayor has to develop a base that is willing to fight for him because they expect to be rewarded if their guy or gal wins.

Results from early and unofficial surveys should already lead to questions about whether President Obama’s chief of staff might find such an army of supporters in big city Chicago politics. Oh, and, the people who elected him to Congress in the leafy, northwest part of the city don’t fit the profile.

Money is not likely to be a problem. The guys in the investment banking business, where Emanuel made over $16 million for less than three years of work, will bankroll him initially. But if he falters early on the campaign trail BY not charming the citizens they are not to throw good money after bad.

So Emanuel has to get his campaign in gear quickly and prove he has the right skills to be mayor. Good luck to him.

At the White House and on Capitol Hill the people who know and appreciate Emanuel’s skills think it will be a loss if he is not behind the scenes running the president’s re-election bid or the Democratic National Committee. In other words they want him to be Atwater.

Juan Williams is NPR Sr. Correspondent and a Fox News contributor.

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