Editor's note: Julian Zelizer is a professor of history and public affairs at Princeton University. He is the author of "Jimmy Carter" and of "Governing America."
Sen. Lindsey Graham warned that Hagel would be the most "antagonistic secretary of defense toward the state of Israel." Neoconservative guru William Kristol is already cranking up the attack machine, focusing on Hagel's statements about Israel and Iran. Although some Democrats are confused about the Hagel appointment, with some upset about remarks he made several years ago about homosexuality, if there is to be a fight it will probably come from the right.
Republicans would do well to avoid this path. In all likelihood, such a nomination fight would only hurt the Republicans, who are already reeling politically from the election and the battle over the fiscal cliff.
Why is a fight over Hagel a bad idea for Republicans? The most obvious is that they would be attacking a member of their own party. Even though Hagel has been a maverick and someone who was critical of his party, pushing in recent years for a centrist approach to foreign policy, he is a genuine Republican, as his voting record reveals.
A mobilized GOP opposition fighting against the inclusion of one of its own in a Democratic administration would only fuel frustration with the rightward drift of the party. After a move that demonstrates Obama's true interest in bipartisanship, this would bolster the critics who say the GOP is to blame for gridlock in Washington.
Hagel is also a staunch advocate for veterans and the military. Republicans have always tried to make the claim that Democrats are weak on defense and that they are the party of national security.
Although Hagel has been a skeptical hawk, he is a Republican hawk nonetheless. One does not have to work too hard to imagine what the optics would be like if Republicans go after Hagel, who would be the first Vietnam veteran to hold the position.
It would give Obama the opportunity to position himself as the person really standing behind a robust national security state. Since taking office, Obama has repeatedly tripped up Republicans on this issue, outflanking them to the right on the war on terrorism. This would simply continue that trend.
The final reason that taking on Hagel is extraordinarily risky for the GOP is that Hagel's most famous maverick move was coming out as a critic of President George W. Bush's war in Iraq despite the fact that he had supported the original resolution to use force if necessary.
Given how unpopular that war remains, a symbol for many Americans of the mistakes that Republicans made on foreign policy when in power, the last thing that Republicans probably want is a renewed debate on Iraq.
By bringing that war to an end, Obama has provided one of the greatest services to the GOP that it could have hoped for, allowing it to move on to other national security issues.
Even some of Hagel's potential liabilities might turn out to be much less significant than expected. After all, despite his comments about Israel, the truth is that Hagel voted to provide Israel with aid and he has voted for sanctions with Iran. The record is much murkier than some of the statements on the Sunday morning talk shows would suggest.
Republicans have often shot from the hip in their attacks on the Obama administration. It is easy to imagine the president and his advisers anticipating attacks on Hagel that will only work to their favor.
Senate Republicans might want to think twice about this vote on a former colleague and focus their attention on more constructive debates.
Follow @CNNOpinion on Twitter.
Join us at Facebook/CNNOpinion.
The opinions expressed in this commentary are solely those of Julian Zelizer.