Call 'em the comeback crew.

Republican Sen. Dan Coats of Indiana and Democratic Sen. Frank Lautenberg of New Jersey served years in the Senate, bowed out because of a term-limits promise or the frustration of endless fundraising and then discovered they couldn't quit the place.

Pleas from party leaders and the opportunity to revise and extend their legacies lured them back. Now in their second acts, at age 68 and 88, respectively, they could be joined by former Democratic Sen. Bob Kerrey, who left Washington in January 2001.

Kerrey, who was Nebraska's governor and two-term senator, faces an uphill fight in trying to win the seat that Democrat Ben Nelson is leaving at the end of the year. Nebraska is a strong Republican state — John McCain beat Barack Obama 57-42 percent in the 2008 presidential race — and outside groups already have labeled Kerrey a carpetbagger who spent the past decade as an academic in New York City.

The decorated former Navy Seal remains undeterred about coming back to a fiercely divided Washington.

"Maybe Olympia Snowe is right: You've got terminal dysfunction and there's nothing that can be done about it," said Kerrey, referring to the moderate Maine GOP senator who just decided against another campaign. "But you tend to be more optimistic about being able to get something done about it when you're on the outside rather than on the inside. ... When you're out, there's a tendency to believe — and I do — that you can make a difference."

Bitter partisanship has stifled plenty of agendas and made Congress an unattractive destination for many, especially with lawmakers held in such low standing. Still, the nation's growing list of problems, from a trillion-plus deficit to salvaging costly entitlement programs, push politicians back to Washington.

"I have to find a Republican that I trust won't cut and run when the heat from their interest group gets turned up and start with him, work with him and stay with him all the way through the end," Kerrey said of tackling the longstanding problems.

Coats served for a decade, from 1989 to 1999, then was ambassador to Germany in George W. Bush's administration and a Washington lobbyist. About two years ago, Republican Sen. John Cornyn of Texas called him about possible candidates with statewide name recognition to run against Sen. Evan Bayh, then a formidable Democratic incumbent with more than $14 million in his campaign account. Coats offered several names; Cornyn said he didn't bother to ask the former senator because it was unlikely he'd come back.

Coats said it was a "put up or shut up" moment. "I thought this is a way to move from kind of yelling at the TV in a frustrated way over what was happening in Washington to get back in the arena and try to do something about it," he said in an interview.

Bayh decided against another bid, Coats survived a tough GOP primary and then easily won the seat in November 2010.

Lautenberg left the Senate in January 2001 after 18 years. Then came Sept. 11 and the terrorist attacks.

"I realized I made a mistake. With my experience, I'm not there, the war is starting, the recession's starting," Lautenberg said in an interview. "I missed it terribly. I felt helpless."

The ethical woes of former New Jersey Sen. Robert Torricelli forced him to abandon his bid in 2002. Democrats scrambled for a replacement and ensured that Lautenberg got on the ballot. He won handily and in the last decade, has fought against privatization of the air traffic control system and pushed for tighter security at seaports and airports.

All told, 35 senators have served nonconsecutive terms since 1913, an illustrious list that includes Republican Barry Goldwater, who reclaimed an Arizona Senate seat in 1969, four years after losing the presidency, and Minnesota Democrat Hubert Humphrey, who resigned in December 1964 to become vice president, ran unsuccessfully for president in 1968 and returned to the Senate in 1971.

In the 2.0 version of Goldwater, he led the Senate Armed Services Committee and joined forces with Rep. Bill Nichols, D-Ala., on the Goldwater-Nichols Act of 1986, a major reorganization of the military's command structure. Humphrey, along with Rep. Augustus Hawkins, D-Calif., pushed for economic legislation embracing full employment and price stability. President Jimmy Carter signed it into law in 1978.

Return engagements are hardly easy, and they weren't exactly smooth for Coats and Lautenberg. Coats faced criticism for not knowing how much he made as a lobbyist and questions about his residency; Lautenberg had to answer for the greased path that allowed him to replace Torricelli despite New Jersey rules.

Kerrey is now a frequent flyer to Nebraska from his home in New York where his wife, screenwriter Sarah Paley, and young son, Henry, live. He hasn't run statewide since 1994 and will have to introduce himself to voters who only recognize the name from Omaha's popular pedestrian bridge spanning the Missouri River.

"Honestly, before his name started being floated as a Senate candidate, all I had heard of him was that he was a former senator and his name was on the pedestrian bridge," said Eric Hansen, a 21-year-old political science major at Creighton University in Omaha.

Kerrey lost part of his right leg in Vietnam and earned the Congressional Medal of Honor. He was governor from 1983-87 and ran for president in 1992. During his post-Senate tenure, he served on the 9/11 Commission and was president of the New School University in New York.

David Kramer, the former Nebraska GOP chairman and 2006 Senate candidate who has been involved in state politics for 30 years, said Republicans will try to define Kerrey for the voters. Outside groups have used radio ads to cast him as a Greenwich Village New Yorker.

"On some levels, I think it's to his advantage to be able to reintroduce himself, because he'll get to define what issues he wants to define himself on," said Kramer, who remembered a "young, single man who dated Debra Winger, and he had that 'it' factor."

Fellow Democrat Chuck Hassebrook stepped aside this week, clearing the way for Kerrey who initially had passed on another bid. Kerrey said if elected, Senate Majority Leader Harry Reid, D-Nev., would honor his previous 12 years, but with no promise based on seniority. Assignments on Armed Services and Agriculture are likely.

Said Republican Coats: "You're legacy is not going to be what you were before. Your legacy is going to be what you did when you were faced with some really tough choices.'

Copyright 2012 The Associated Press.