Top advisers to Joe Arpaio on Tuesday batted down suggestions that the former sheriff's Senate candidacy was a fundraising stunt or ruse to keep the Republican's name in the news.

Arpaio, in an exclusive interview with the Washington Examiner, announced his bid for the Arizona seat being vacated at year's end by Republican Sen. Jeff Flake. The reveal followed calls by Arpaio's advisers to Republican operatives connected to the White House, and directly to the National Republican Senatorial Committee, the Senate GOP campaign arm, to inform party leaders of his campaign.

Arpaio turns 86 in June, feeding speculation that the close ally of President Trump wouldn't follow through. But Chad Willems, Arpaio's political adviser since 2000, said in a telephone conversation that there was nothing phony about his candidacy.

"People still don’t believe it — the local media think it’s a joke, that it's to get the sheriff press attention," Willems said. "But this is really happening; this is a real campaign. We're off and running."

Willems was in the process of assembling a campaign team and building an infrastructure. In an interesting twist, Willems is president of the same Phoenix firm, The Summit Consulting Group, Inc., that advises Flake and would have handled his campaign had the first-term senator not retired. Summit's Steve Voeller, who previously worked for Flake, was the lead on the re-election until the senator pulled the plug.

Arpaio served as the elected sheriff of Maricopa County, which encompasses Phoenix and surrounding suburbs, for 24 years until a Democrat ousted him in 2016. Trump pardoned Arpaio last summer, sparing the polarizing yet iconic lawman, known nationally for his staunch opposition to illegal immigration, jail time after he was convicted of ignoring a federal court order in a racial-profiling case.

White House press secretary Sarah Sanders declined to comment on Arpaio's campaign during Tuesday's briefing with reporters. The race to succeed Flake represents one of the few pick-up opportunities in the Senate for the Democrats, who were openly rooting for Arpaio to win the late August Republican primary.

The Democrats would much rather face Arpaio in the midterm than Rep. Martha McSally, 51. She is positioned to appeal to Arizona's rising nonwhite population and voters in the state's influential Phoenix suburbs — two blocs that are sour on Arpaio and Trump.

Sources confirmed to the Washington Examiner that the Republican congresswoman would announce her bid on Friday. According to an invitation to the event, it was set to be held at an airplane hanger in Phoenix. McSally, an Air Force veteran, represents a swing district in Southern Arizona, and is the preferred candidate of Republican congressional leaders in Washington and GOP leaders in the Grand Canyon State.

Arpaio said he wasn't intimidated by McSally — or Kelli Ward, the other Republican in the race. Ward is not considered formidable but could secure enough support in the primary from voters who favor insurgent candidates to cause Arpaio a problem and pave the way for McSally. It's also possible that voters who have been backing Ward for lack of options defect to Arpaio, who is beloved by many on the Right.

"Everybody has a right to run for office, I’ll take my resume against her or anybody, so I’m not concerned about it," Arpaio said. "She has a right to run. The other candidate — Kelli Ward — she has the right; I’m sure she was very happy that Steve Bannon endorsed her."

Bannon had been leading a 2018 insurgency against the Republican establishment until comments critical of Trump and his family were publicized in a new book caused the president and his financial backers to disavow him. Bannon, Trump's former campaign CEO and chief strategist in the White House, stepped down from his position of executive chairman of Breitbart News on Tuesday in a move interpreted as a firing.