After returning to the United States, Flake served as executive director of the Goldwater Institute, before being elected as a Republican to the House of Representatives from Arizona's 1st congressional district in 2001.

[14] He took a two-year leave of absence to serve as a missionary for the Church of Jesus Christ of Latter-day Saints in South Africa and Zimbabwe in the early 1980s.

Shortly after being elected for a third time, Flake announced in early 2005 that he had changed his mind on pledging term limits and was planning to run for reelection in 2006.

[23] After the race tightened, the Wall Street Journal criticized a controversial Flake ad that accused Carmona of having "issues with anger, with ethics, and with women.

"[24] Flake was endorsed by the Casa Grande Dispatch,[25] the United States Chamber of Commerce,[26] the Senate Conservatives Fund,[27] and the Club for Growth.

Senator Martin Heinrich (D-NM) were featured on a Discovery Channel reality TV show, Rival Survival, where the two stayed on a small Micronesian island for six days.

[54] A "scourge of pork-barrel spending",[55] Flake was ruled the least profligate spender in Congress by Citizens Against Government Waste in July 2007 and designated a "taxpayer superhero.

Starting in May 2006, he became prominent with the "Flake Hour," a tradition at the end of spending bill debates in which he asked earmark sponsors to come to the house floor and justify why taxpayers should pay for their "pet projects.

[61] In September 2018, Flake was among six Republican senators, Mike Lee, Pat Toomey, Rand Paul, David Perdue, and Ben Sasse, as well as Bernie Sanders, that voted against a $854 billion spending bill, meant to avoid another government shutdown.

[68] In August 2017, Flake published his book Conscience of a Conservative: A Rejection of Destructive Politics and a Return to Principle, which expanded on his criticisms of Donald Trump.

[35][36] In May 2018, Flake said that Trump had "debased" the presidency, that he had a "seemingly bottomless appetite for destruction and division," and that he possessed "only a passing familiarity with how the Constitution works.

“If condoning the President’s behavior is required to stay in the Party’s good graces, I’m just fine being on the outs,” Flake wrote on Twitter before the vote.

Flake and McCain asserted in their letter that little proof existed to back up such a conclusion, but the EPA responded by saying that the proposed regulation was carefully examined and was made with bipartisan input.

At a 2008 congressional hearing featuring General David Petraeus, Flake said, "I still have a hard time seeing the big picture and what constitutes success [in Iraq].

[93] Flake supported President Barack Obama's 2014 decision to begin the process of normalizing relations between the United States and Cuba, despite opposition to the policy change from other Republican senators.

Flake joined Democrats Chris Van Hollen and Patrick Leahy on a trip to Cuba to return Alan Gross to the United States.

Gross, an American government contractor, had been imprisoned in Cuba for five years but was released as part of the agreement between Obama and Cuban leader Raúl Castro.

Just days before the vote, he had sent the mother of one of the Colorado theater shooting victims a handwritten letter stating that "strengthening background checks is something we agree on.

"[97] In response to a question asking whether he was worried about potential political consequences vowed by gun-control groups, Flake replied, "That's the beauty of a 6-year term.

[105] The bill would have authorized students who earned a Ph.D. in a science, technology, engineering, or mathematics from U.S. universities to be admitted for permanent residence and to be exempted from the numerical limits on H-1B nonimmigrants.

"[114] Flake spoke out against President Donald Trump's January 2017 executive order to prohibit immigration from seven predominantly Muslim countries.

"[115] In 2015, Flake and Senator John McCain published a report detailing what they called "paid patriotism" by the U.S. Department of Defense for using soldiers, military equipment and resources at professional sports events in the United States.

"[120] During the 2005 debate on renewal of the expiring provisions of the USA Patriot Act, Jeff Flake successfully submitted several amendments to the bill in the House of Representatives.

[121] Two of his amendments were signed into law and they subjected any National Security Letter and its gag order to a judicial challenge by the recipient, and narrowed the scope of "Sneak and Peek" warrants to have definite time limits on their duration and extensions before they need to notify the target of the investigation.

"[129] Flake received $22,700 in donations from paid lobbyists representing Internet service providers and tech firms to sponsor the anti-privacy legislation.

[130] In April 2017, the legislation passed both houses of Congress, which were Republican-controlled, allowing ISPs to sell consumer browsing history and other information without the user's consent.

[140] In March 2016, Flake said that Judge Merrick Garland, President Barack Obama's nominee for the Supreme Court seat vacated by the death of Antonin Scalia, should not be confirmed unless Hillary Clinton won the 2016 presidential election.

Kavanaugh had been accused of sexual assault by a number of women, including Dr. Christine Blasey Ford, who testified for several hours before the Senate Judiciary Committee the day before Flake's announcement.

[150][152] In November 2018, Flake was one of twelve Republican senators to sign a letter to President Trump requesting the United States-Mexico-Canada Agreement be submitted to Congress by the end of the month to allow a vote on it before the end of the year as they were concerned "passage of the USMCA as negotiated will become significantly more difficult" if having to be approved through the incoming 116th United States Congress.

[157] Having enjoyed the experience, he decided to repeat it when he was a senator, this time bringing his two youngest sons with him to another island in the area, Biggarenn, for four days during a congressional recess in 2013.