The Washington Post’s Al Kamen of In the Loop looks at the transition of Obama’s second term. (The Washington Post)

The nomination of former senator Chuck Hagel to lead the Pentagon has set in motion a highly unusual campaign-style brawl over a Cabinet post long considered above politics.

Supporters and opponents are raising money and building political organizations in anticipation of a grueling and contentious Senate confirmation process.

The opponents, led by a conservative group called the Emergency Committee for Israel, began airing attack ads soon after the Nebraska Republican’s name surfaced weeks ago and on Monday rolled out a Web site,, to lay out its case against him. The group has questioned Hagel’s commitment to the security of the Jewish state and accused him of being soft on Iran.

White House officials, meanwhile, have begun an aggressive push to introduce “the real Chuck Hagel,” recruiting high-profile endorsements and contacting potential critics in an effort to neutralize opposition. For the first time since his name was floated, “the White House is putting its full muscle” behind Hagel, said a person familiar with the process.

In the past week, fundraising has become a priority for both sides, introducing a new element of electoral-style politics into a realm that has seldom, if ever, seen it before.

A group of Hagel’s backers, led by Richard Burt, a senior diplomat in the Reagan administration, formed a nonprofit organization and solicited contributions from donors active in foreign policy and defense. Burt said the aim was to prepare a public response to what they said was unfair criticism and make sure “Hagel was not whittled down” before he was nominated. With President Obama officially naming Hagel on Monday and the White House bolstering its defense of the nominee, Burt said his group will refund the donations.

As Burt’s group was getting started, another organization, the Bipartisan Group, hired the Podesta Group, a lobbying firm, to promote Hagel’s credentials.

The escalating campaigns come amid what has already been a flurry of published letters, op-eds, and print and broadcast advertisements.

Officials at the Emergency Committee for Israel said Monday that they are ramping up a substantial online ad campaign, buying Google keywords and placing ads on Facebook and Twitter to drive traffic to their new anti-Hagel Web site. “Anyone concerned about Chuck Hagel is going to see what we have to contribute to this debate in the coming weeks,” said Noah Pollak, the group’s executive director.

The Log Cabin Republicans, a group that supports gay rights, purchased a full-page ad in Monday’s Washington Post recalling Hagel’s 1996 statement supporting the Defense of Marriage Act, as well as a statement he made in 1998 referring to an ambassadorial nominee as “openly, aggressively gay.” The ad notes Hagel’s recent regret for his past comments and labels the apology “Too little, too late.” Gregory T. Angelo, the group’s interim executive director, declined to say how much money the group raised for the anti-Hagel ad.

The battle lines are being drawn so sharply because of the high stakes on all sides.

For neoconservatives, who dominated foreign policy during George W. Bush’s presidency, Hagel represents a threat to their continued influence at the Pentagon. He was critical of Bush foreign policy initiatives in Iraq and Afghanistan and has challenged the influence of pro-Israel activists on U.S. foreign policy.

Obama, who is seeking to define a strong foreign policy at the start of his second term, wants to avoid another nomination setback. Susan E. Rice, his top choice for secretary of state, withdrew from consideration last month amid relentless criticism from Republicans.

“I don’t think the president can afford to lose another skirmish,” said Abraham Foxman, president of the Anti-Defamation League.

Foxman has been a leading critic of Hagel’s record and past statements. After a call over the weekend from a White House official, he issued a carefully modulated statement Monday saying that “Hagel would not have been my first choice, but I respect the President’s prerogative.”

In some cases, the White House’s entreaties have met with resistance. When an official spent 20 minutes on the phone with David Harris, executive director of the centrist American Jewish Committee, arguing that there was “no need to worry” about administration positions on Israel and Iran, Harris said he responded, “We’re going to be watching the Senate confirmation hearings, listening carefully, and we’ll determine then our position.”

White House senior adviser Valerie Jarrett called gay rights groups last month to try to reassure them. Obama aides have called liberal allies and others in recent days to seek support — or at least neutrality — from activist groups.

Talking points distributed Monday to liberal commentators and activists featured Hagel’s recent apology and statement expressing his support for the gay rights movement. The talking points also detailed Hagel’s record as a decorated Vietnam War veteran and included a series of pro-Israel statements, according to a person who received the e-mails.

The dispute over Hagel’s nomination spread Monday to Capitol Hill, where Republicans were sharply critical of Obama’s announcement and even some of the president’s closest allies stopped short of promising to confirm the nominee.

“Chuck Hagel, as a former colleague and a patriot with a decorated service record, has earned the right to nothing less than a full and fair process in the Senate,” said Sen. Charles E. Schumer (D-N.Y.). “I look forward to fully studying his record and exploring his views.”

Some Democrats expressed unqualified support. Senate Majority Leader Harry M. Reid (Nev.) lauded Hagel’s “deep understanding of the national security establishment.” He added: “Few nominees have such a combination of strategic and personal knowledge of our national defense needs.”

There have been fights in the past over presidents’ nominees, but longtime observers say the attacks on Hagel’s policy positions are unprecedented.

“I have never seen anything like this,” said Lawrence J. Korb, an assistant secretary of defense during the Reagan administration. He and others recalled the clash over former senator John Tower’s nomination to be defense secretary in 1989. But the objections in the Texas Republican’s case turned on questions of morality and character, not policy. Korb added that he is optimistic that Hagel will be confirmed.