Others who have spoken out against Hagel include leaders from the Anti-Defamation League, a Jewish advocacy organization, and the Israel Project, a pro-Israel educational group, as well as Rep. Tom Cotton, R-Ark., and Sen. Ted Cruz, R-Texas, who said on "Fox News Sunday" that President Obama's decision to choose Hagel showed he is "high on reelection right now." Some on the left, too, have taken issue with remarks Hagel made in the past about Washington's "Jewish lobby," and his assailment in 1998 of then-President Clinton's nominee for ambassador to Luxembourg, James Hormel, as "openly, aggressively gay," and whose ability to do an effective job may be impaired by his sexual orientation. Hagel last month issued an apology for his "insensitive" words.

Still, Hagel has supporters rallying in his corner. Sen. Heidi Heitkamp, D-N.D., said on ABC's "This Week" that the dust-up a potential Hagel nomination has created is "the kind of fight... that the people of this country get so frustration about, and with. Let Chuck Hagel get nominated, if he's going to be nominated, and let's hear what the senator has to say." Senate Majority Whip Dick Durbin, D-Ill., also defended Hagel on CNN's "State of the Union" as a "serious candidate," and celebrated his status as "a decorated veteran of the Vietnam war a person that includes service on the Foreign Relations Committee as well as the Intelligence Committee."

President Obama, for his part - after U.N. Ambassador Susan Rice removed her name from consideration for secretary of state amid controversy over her classification of the 9/11 attack in Libya - is eager to prove he won't buckle under outside pressure, and has continued to stand by Hagel. During an appearance on "Meet the Press" last week, the president praised him as "as patriot."

"He is somebody who has done extraordinary work, both in the United States Senate, somebody who served this country with valor in Vietnam, and is somebody who's currently serving on my intelligence advisory board and doing an outstanding job."

If Hagel is confirmed to the Cabinet post, one of his first responsibilities at the Pentagon will be the withdrawal of troops from Afghanistan, set to start in 2014.