With less than a week to go until Election Day, Republican and former Nebraska Sen. Chuck Hagel gave his support Thursday afternoon to Democrat Bob Kerrey’s campaign for Nebraska’s open U.S. Senate seat, an unexpected splash in a tight Senate race against Republican Deb Fischer.

Both Hagel and Kerrey, whose past terms in the U.S. Senate overlapped, are known for breaking with their party lines – Hagel over the Iraq War, Kerrey over immigration and other issues. With today’s highly divisive politics, Hagel said, that willingness to meet opponents in the middle is exactly what Nebraskans need in Washington.

“Bob was a Democrat and I was a Republican, but it didn’t matter,” Hagel told the assembled group, echoing Kerrey’s frequent references to bipartisanship throughout his campaign. “We were serving the interests of the same people in the same state in the same country.”

Kerrey and Hagel announced the endorsement together in Lincoln, where they met with about 60 supporters and reporters in the Nebraska State Capitol Rotunda. Hagel, who retired from the Senate in 2008 and moved away from Nebraska, said the rotunda has particular significance to him: There, he announced his Senate candidacy in 1995. He said the Capitol, home to a nonpartisan, one-chamber legislature, symbolizes the need for political moderation and unity.

Hagel and Kerrey both served in the Vietnam War, after which Kerrey was awarded a Medal of Honor. Hagel said military experience is more important than ever when neither President Barack Obama nor Mitt Romney, candidates for the presidency, are veterans.

“When you commit a nation to war … you’d better be damn sure what you’re talking about,” Hagel said.

Meanwhile, Fischer gained her own endorsement in Omaha on Thursday from U.S. Sen. John McCain of Arizona, who ran against Obama in 2008.

Prominent Nebraska Republicans quickly dismissed Hagel’s endorsement, downplaying its significance and rallying around Fischer, a state senator from Valentine. Gov. Dave Heineman and current Sen. Mike Johanns, who is not up for re-election this year, pointed out Hagel’s well-known opposition to George Bush’s policies in Iraq as a point against Hagel’s Republican credentials.

Hagel affirmed at the Capitol he is still a Republican, but said he and Kerrey largely agree on Social Security reform, foreign policy and other issues. Kerrey said he appreciated Hagel’s cross-party endorsement.

“This is an example of what we have to do,” Kerrey said. “It’s easy to take criticism from your enemies. What’s difficult is taking criticism from your friends when you’re doing what you think is right.”

In a press conference in Omaha Thursday morning, Johanns also suggested Hagel was trying to score political points with the Obama administration.

“I think Chuck would love to think he’s on the list to be secretary of something,” Johanns said.

Hagel, who currently serves as co-chairman of the bipartisan Presidential Intelligence Advisory Board, bluntly dismissed that idea.

“(Johanns) doesn’t know anything about who I am,” he said to applause from the crowd of Kerrey supporters. “I’ve got a pretty full agenda.”

Hagel added jokingly, “If that’s my motive, what the hell am I doing in Nebraska? I can assure you I’d be probably in Ohio.”

No one asked him for an endorsement, Hagel said, but he decided Sunday to call the Kerrey campaign.

“You look over the past two or three months and it gets closer to the election,” Hagel said in a brief interview after the conference. “So I called him and asked, ‘Is there something I can do to help?’”

The endorsement comes as the Nebraska Senate campaign sprints into its final days. Over the past several months, the race has gone from a double-digit lead for Fischer to nearly neck-and-neck.

At a Kerrey campaign stop on the University of Nebraska-Lincoln campus last week, political science professor John Hibbing said that trend reflects growing comfort for Congressional Democrats across the country.

“Things are looking better for the Democrats for holding their Senate majority,” mostly because of circumstances specific to each state, Hibbing said.

Kerrey said Thursday he expects Hagel’s endorsement will only help his chances.

“I believe that we’re closing,” Kerrey said, “and it’s reasonable for me to have some expectation that on Nov. 6, we’re going to win.”