His opposition to pork-barrel spending has proved popular in the past, but Flake faced criticism during the race to succeed retiring Republican Sen. Jon Kyl that his crusade has hurt efforts to attract new businesses to the state.
"Arizona is far better without earmarks," a confident Flake said during an October debate.
Flake, who has represented cities in eastern metro Phoenix in Congress since 2000, won the Senate seat over independent-turned-Democrat Richard Carmona, who served as President George W. Bush's surgeon general.
Before Carmona entered the race a year ago, both parties viewed Flake as the overwhelming favorite. The contest grew more competitive after Flake emerged from a bruising primary against a wealthy businessman who put $6 million of his own money into the race and outside groups threw in about $15 million into the general-election contest in October.
Flake has supported Republican priorities over the years, but also has sided with Democrats on other issues.
In the past, Flake opposed the rescue of financial firms during Bush's administration, the 2010 health care overhaul and the 2009 economic stimulus package. He has applauded the Obama administration's decision to lift a ban on travel and remittances to Cuba.
Flake has been criticized for changing his immigration views. He supported proposals in the past that would have revamped guest-worker programs and created a pathway to citizenship for illegal immigrants. But he took a narrower position when he announced his Senate candidacy last year, saying voters won't trust government to fix the nation's immigration woes unless it can first secure the U.S.-Mexico border.
When Connecticut Democrat Chris Murphy neared the end of his victory speech in a bruising U.S. Senate race Tuesday night, he returned to the story of his mother rising out of poverty and what the election meant for a fictional girl living in a public housing complex.
The three-term U.S. congressman said voters gave the girl a better chance at a brighter future.
"She's wondering whether that promise that was made to my mother — work hard, play by the rules and you'll have a chance to make it — is still alive," he said. "She's going to wake up tomorrow and know that that chance to be great ... is just a little bit closer. And in the end my friends, that is the most important measurement of what we've done here tonight."
Murphy defeated Republican former wrestling executive Linda McMahon in the race to succeed retiring independent Sen. Joe Lieberman, touting his commitment to the middle class and accusing McMahon of favoring the rich. In the process, he survived McMahon spending $42 million of her own money, $8 million short of what she spent in her unsuccessful bid for Senate in 2010.
He also survived McMahon's attacks on his past financial problems, which included late mortgage and property tax payments, despite McMahon's own bankruptcy years ago.
His victory was part of Democrats' sweep of five congressional races in Connecticut.
Murphy, who served eight years in the state legislature before going to Congress, said his priorities include reforming the tax code to help small businesses, promoting and strengthening American manufacturing, rebuilding roads and rails, improving education and growing the renewable energy industry. He agrees with President Barack Obama on most social and economic issues.
Bridging the bitter divide between Democrats and Republicans in Washington has been another of his goals. He is a co-chairman of the Center Aisle Caucus, a bipartisan group of House members trying to promote civility and positive dialogue in Congress.
While campaigning for U.S. Senate, U.S. Rep. Mazie Hirono rarely shied away from fierce support of Democrats and consistent criticism of Republicans, arguing that her party's stances better reflect the values of Hawaii.
Now, after trouncing former Hawaii Gov. Linda Lingle, Hirono is embracing her standing as the state's first woman to serve as senator and the Senate's first Asian-American woman.
Hirono told The Associated Press after winning Tuesday night that the historical footnote says more about the makeup of the country's electoral pipeline.
"What it reflects is that we need a lot more diversity in the United States Senate," said Hirono, who was born in Fukushima, Japan. "I'm going to do my part to support more women to run for Congress and certainly support more minority candidates."
Hirono, 65, moved to Hawaii with her mother in 1955, then went on to practice law in Honolulu before she was elected to the Hawaii Legislature in 1980. She was elected as lieutenant governor in 1994 and 1998, then lost a governor's race to Lingle in 2002. She was elected to the U.S. House in 2006, and is generally considered one of its more liberal members.
Hirono ran on a platform of stopping Lingle as a representative of national Republican interests. At every turn in the race, Hirono linked her opponent with well-known GOP names including Mitt Romney, Paul Ryan and George W. Bush.
Hirono held court for Democrats in a state known to support the party. President Barack Obama topped the ticket for Democrats in his birth state in his bid for re-election.
While Hirono didn't win as much support as Obama in the state, she beat Lingle with nearly 62 percent of the vote compared with nearly 37 percent for Lingle.
Hirono has followed other Democrats on several issues, including Obama's jobs plan and health care reform.
Democrat Joe Donnelly is a three-term congressman from northern Indiana who ran as a centrist highlighting his support for extending the George W. Bush-era tax cuts while fending off attacks over his support for the federal health care overhaul.
He was born in Massapequa, N.Y., and received bachelor's and law degrees from the University of Notre Dame in South Bend, Ind. He worked as an attorney and ran a printing business before defeating Republican Rep. Chris Chocola in 2006. He had lost to Chocola him two years earlier.
Donnelly entered the U.S. Senate race after GOP-controlled redistricting moved a couple strong Republican counties into what had been a swing district.
The Senate race turned in Donnelly's favor after Republican Richard Mourdock said in a debate that pregnancies resulting from rape are something "God intended." Donnelly, meanwhile, twice supported a bill that would have denied federal abortion funding even in cases of rape and incest.
Donnelly positioned himself during the campaign as a bipartisan problem-solver against the tea party-backed Mourdock, who defeated longtime Sen. Richard Lugar in a contentious Republican primary.
Donnelly, 57, and his wife, Jill, have two children.
When asked about his vote of the federal health care law, he told the story of his daughter, who takes Enbrel for her rheumatoid arthritis, at a price tag of $1,500 a month. Donnelly says he worried about people who can barely pay their rent being able to afford such drugs.
"How do they make it so their daughter doesn't have to go in a shower stiffened up every single day, as opposed to being able to get this prescription?" he said.
Independent Angus King may be just starting out in his new role as a U.S. senator, but he's long been a well-known figure in Maine whose independent politics have been his calling card.
The 68-year-old King was Maine's governor for two terms between 1995 and 2003, establishing credentials as someone who could work with both parties. Before that he spent 18 years as a public broadcasting commentator on state public policy issues.
Angus Stanley King Jr. was born in Alexandria, Va., grew up there in a politically active family, and after law school at the University of Virginia came to Maine as a lawyer serving low-income people.
He later went to work for William Hathaway, the Democrat who ousted entrenched Republican Sen. Margaret Chase Smith from her Senate seat. Hathaway's election in 1972 led to King's appointment to staff of the Senate Labor Committee.
With King's 2012 election, he returns to the national political stage — only on a different level. Then, he was refining policy. Now, he's in a position to shape policy in a much more polarized environment, said Rutgers University political science professor Ross Baker.
Asked whether King will have any influence in Washington, Baker said, "Just ask Joe Lieberman," referring to the Connecticut independent who is retiring. "Independents have a huge impact."
Being independent wasn't always easy, but King made it work.
He walked into a state government on rocky fiscal ground in which cutbacks were required to keep the books balanced. But gradually, as the economy improved, state tax revenues poured in beyond anticipated levels.
King was involved in hydropower and energy conservation work before running for governor, and after serving got involved in wind power. He sold his stake in the wind company when he ran for Senate.
On the campaign trail, Democrat Elizabeth Warren told supporters she never envisioned jumping into the rough and tumble of electoral politics — let alone making the U.S. Senate the object of her first campaign.
Now the 63-year-old is preparing for the transition from the upper echelons of academia at Harvard Law School to the halls of Washington, where she will occupy the seat once held by Democratic Sen. Edward M. Kennedy.
Warren was born in Oklahoma City on what she has called "the ragged edge of the middle class." Her father sold carpeting and worked as a maintenance man and her mother answered phones at Sears. Her first job was waiting tables in her aunt's Mexican restaurant when she was 13.
She became a teacher after earning a bachelor's degree from the University of Houston in 1970. Six years later she earned a law degree from Rutgers University and began a career as a law professor, going on to become a pre-eminent expert in the fields of bankruptcy and commercial law.
She came to prominence nationally following the financial collapse of 2008, when she was tapped to serve as chair of the Congressional Oversight Panel for the Troubled Asset Relief Program, which authorized the U.S. Treasury to spend $700 billion to stabilize the economy.
She pushed for the creation of a new federal agency to hold the nation's largest financial institutions accountable by protecting consumers from "tricks and traps" hidden in mortgages, credit cards and other products.
She then turned her sights on the U.S. Senate, announcing she would challenge Republican incumbent U.S. Sen. Scott Brown, who won a special election in 2010 to fill the seat left vacant by Kennedy's death.
The massively expensive race, the most costly in state history, turned harsh at times, with Brown charging that Warren had used her claims of Native American heritage to help her academic career.
The two remained neck and neck in public opinion polls until Election Day, when voters handed Warren a 54 percent to 46 percent margin over Brown, making her the first woman in Massachusetts elected to serve in the U.S. Senate.
Republican Deb Fischer's rise from little-known rancher and state senator to Nebraska's U.S. senator-elect completes the deeply conservative state's move to full Republican domination — just one goal of the rock-ribbed conservative.
Fischer, 61, handed Democrat Bob Kerrey his first loss in Nebraska, handily defeating the former governor and two-term U.S. senator in a race that had been perceived as close.
Friends and political strategists have said Fischer's success was a combination of hard campaigning in some of Nebraska's most isolated hamlets, her appeal as a conservative rancher, and a flood of outside money that paid for relentless television ads attacking first her better-known and better-funded primary opponents, then Kerrey in the general election.