Now, Franks' hand-picked successor, Steve Montenegro, a former state senator, is grappling with his own scandal involving a former female subordinate.
The story, which broke last week, could lead to Montenegro, who had been considered the race's front-runner, being surpassed by a former state Senate colleague, Debbie Lesko, in a conservative district. The winner of Tuesday's GOP primary is heavily favored to win the general election in April.
"I’ve been a big fan of Steve Montenegro's in the past," Rose said. "But it’s just incredible hypocrisy. His entire political profile has been puritanical."
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Montenegro is a Christian minister who has emphasized "virtue, honor and integrity" in his campaigns and features a photo of himself posing with his wife and young daughter on his website.
Last week, media outlets obtained text messages that The Arizona Republic described as "flirty" between Montenegro and a former state Senate aide, including a late-night message telling her he wished she had come on a work trip after she texted him a topless photo of herself.
Montenegro initially dismissed the reports as "false tabloid trash." But in an interview with The Washington Examiner, he acknowledged receiving the topless photo, but said he immediately cut off contact with the woman and told his wife.
"I want you to know I did not have any inappropriate relationships with this woman," he told the Examiner. "If there is anything, I would say I’m guilty of it's becoming too comfy or familiar as seen in some of those texts."
The controversy has led a number of Arizona Republicans — mainly women — to call on Montenegro to withdraw from the race. They include a leading anti-abortion activist, a state senator and former Gov. Jan Brewer, who has endorsed Lesko.
"The circumstances in which the predecessor, Congressman Trent Franks, left the office strongly suggest that nothing short of a full in-person denial of these events by Mr. Montenegro himself should suffice," Brewer said in a statement on Twitter.
Arizona's secretary of state, Michele Reagan, a Republican, said taxpayers were the victims of lawmakers' inappropriate relationships. "They don't pay us to go there to indulge in fantasies w/staff," Reagan tweeted.
However, the political impact of the scandal may be blunted by the fact that many voters have already cast their ballots, taking advantage of Arizona's widespread use of early voting.
"To say this is hurting him is a massive understatement, but the million-dollar question is how much of the early vote did he bank before it broke?" asked Phoenix-based GOP pollster Mike Nobel of OH Predictive Insights.
Montenegro was seen as the favorite in the crowded primary field, thanks to strong fundraising and endorsements from Franks (who appeared in a Montenegro ad); Sen. Ted Cruz, R-Texas; ex-Maricopa County Sheriff Joe Arpaio; former presidential candidate Rick Santorum; and the evangelist James Dobson.
Lesko, the only major female candidate in the contest, has the endorsement of the chairman of the conservative House Freedom Caucus, Rep. Mark Meadows, R-N.C. And she was tied with Montenegro in the most recent poll, followed by Phil Lovas, the state chairman of President Donald Trump's 2016 campaign, and Bob Stump, a former chairman of the Arizona Corporation Commission.
"Those people who were already on the fence, especially female Republicans, are probably breaking towards Debbie," said Chad Campbell, a Democrat and former minority leader of the Arizona state House.
Few think Democrats have a realistic shot of winning the election, since the district skews older, white and conservative. Hiral Tipirneni, a physician, is seen as favored to win the party's primary on Tuesday.
But if Montenegro ekes out a victory on Tuesday, it would set up the potential for a long-shot upset by a Democrat against a damaged GOP candidate.
"In this environment, anything can happen," Campbell said.