Chuck Hagel, whose confirmation hearing in the Senate was highly contentious, was finally confirmed today as the next secretary of defense by a vote of 58-41.

The nomination was in some serious doubt in the last few weeks, especially after Hagel endured some very tough questioning from Republican members of the Armed Services Committee. In the end, though, four members of the GOP joined 54 Democrats to confirm him. The four Republicans were Thad Cochran (Miss.), Mike Johanns (Neb.), Richard C. Shelby (Ala.) and Rand Paul (Ky.).

It is the closest vote ever for an incoming secretary of defense. The source of much of the tension between Hagel and his former colleagues in the upper chamber of Congress is likely Hagel's criticism of the Iraq War during his time in the Senate and after. However, this may have helped build his relationship with President Obama. The two men met and became friendly while serving together on the Senate Foreign Relations Committee.

Hagel will become the first enlisted man to lead the Pentagon, a historic ascension for the former senator from Nebraska. He will replace the departing Leon Panetta.

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