Whenever the initial glow of a presidency begins to fade, there's a race among critics to find a compelling Rasputin or a group of gray eminences pulling the levers of the presidency in the wrong direction.

The critics of Barack Obama's administration are no different.  Today's reputed culprits are the so-called gang of four:  Rahm Emanuel, the chief of staff; Valerie Jarrett, Obama's longtime friend and backer from Chicago; David Axelrod, his chief political strategist; and Robert Gibbs, the White House spokesman.  They have been widely accused of isolating, manipulating, and now damaging, the president.

What's surprising about that these charges is that the person closest to the president, his wife, is somehow left out of the picture.  Those in search of scapegoats in the past often looked to first ladies as the causes of their husband's difficulties.  However anodyne Michelle Obama's public image has become -- with fashion magazine covers, visits to schools and tours of vegetable gardens -- few people doubt her intelligence and passion for favorite causes and ideas.

Is she possibly the real power behind the throne?

First ladies have had tremendous influence over the men they're married to ever since the days of the first to live in the White House, Abigail Adams, whom some regarded almost as a co-president.  In the 20th century, there have been the formidable examples of Woodrow Wilson's second wife, the jewelry heiress Edith Galt, who was believed to have run the executive branch single-handedly after 1919 following her husband's stroke; Eleanor Roosevelt, a political force of nature; and perhaps the most intimidating first lady in recent memory, Nancy Reagan.

The interesting thing about these women is that they tended to have as much impact on the structure of decision-making as on particular decisions themselves.  No president is a dictator, and the workings of a presidency are often determined as much by the nature and composition of the staff -- how their various pieces fit together -- as they are by specific arguments, personalities and even politics.  The favor or disfavor of a strong-willed first lady -- especially one well trusted by the president -- can be critical in this regard.

Such first ladies are the ultimate arbiters of the inner circles because they have tended to cast the final vote on who gets in and who is cast out.  Chances are that Michelle Obama falls within this category, in contrast to other recent predecessors -- Pat Nixon or Betty Ford, for example -- whose roles were more those of onlookers, or those who were cast as foils or as competitors to the staff and cabinet, such as Hillary Clinton or Rosalynn Carter.

The executive machinery of the White House can seem unpredictable and ineffective from the outside, as it did so often under Wilson, FDR and Reagan.  But when the role of the first lady is understood and taken into account, that machinery actually functions according to a clear and firm inner pattern.

This is not necessarily a bad thing.  The best first ladies -- and some day first gentlemen -- can be sources of strength, resolve and clarity.  Few are in a so strong a position to speak truth to power.  But there's always the potential for abuse, for a president's spouse to be over-protective and duplicitous and to convert the presidency into a classic court of intrigue.

It's of course impossible to determine the culture of this White House from a distance.  Nobody but a few insiders knows the truth of Michelle Obama's relationship with her husband and his staff.  But the president's penchant for keeping his inner circle tight suggests that he fears being mistreated or distracted, and that he likes a firm hand on the rudder.  That hand may very well be hers.

This piece was distributed for non-exclusive use by the History News Service, an informal syndicate of professional historians who seek to improve the public's understanding of current events by setting these events in their historical contexts. The article may be republished as long as both the author and the History News Service are clearly credited.