Now I am running for Senate.
Ward, who has been backed by former White House chief strategist Stephen Bannon, has framed her campaign as an extension of Trump's "America First agenda", although that could be more hard now that Trump is feuding with Bannon. A third candidate in the Republican primary is former State Senator Kelli Ward, an avid Trump supporter who has advocated for one of the president's campaign promises - a border wall with Mexico.
Democrats need to pick up two seats this November to wrest control of the U.S. Senate from the Republicans. Republicans hold a 51-49 advantage in the chamber.
McSally also compared her own political style to the president, saying in her announcement video, "Like our president, I'm exhausted of PC politicians and their BS excuses". As she launched her bid, the 2nd District Arizona lawmaker called for the national Republican Party to, "grow a pair of ovaries", among what will be one of the most watched Senate races in the country.
She highlights her fight as a member of the Air Force against a policy in Saudi Arabia requiring female personnel to dress in traditional Muslim attire.
McSally also co-sponsored an immigration plan released by House conservatives this week that would reduce legal immigration levels by 25 percent, block federal grants to sanctuary cities and restrict the number of relatives that immigrants already in the USA can bring here.
"I absolutely refused to bow down to Sharia Law", McSally says in the video. "After eight years of fighting, I won my battle for the religious freedom of American servicewomen".
Arpaio, who entered the race on Tuesday, was pardoned by Trump previous year after being convicted of criminal contempt of court for refusing to obey a court order in a racial profiling case focusing on Hispanics targeted as potential illegal immigrants.
"Throughout his time as Sheriff, Arpaio continued his life's work of protecting the public from the scourges of crime and illegal immigration", Trump said in a statement at the time.
But she has also voted with Trump, a fellow Republican, almost 97 percent of the time. Arpaio told CNN on Wednesday that he still thinks Obama's birth certificate is fake, despite clear evidence it is not.
Republicans lost a Senate seat last month to Democrats in Alabama after Trump and other Washington Republicans in the state's GOP primary backed conservative firebrand Roy Moore over the more moderate Luther Strange.
Several Republican political consultants said Arpaio's prolific fundraising and strong name recognition could marginalize Ward's campaign, which has targeted the same bloc of Trump voters.
"We've been with Martha since her first campaign and we just want to be able to say we knew the first female president back when", he said.
The success of her message will help determine whether it's finally time for Republican candidates to heed party leaders who warned six years ago that candidates must soften their tone on immigration and do far more to connect with Hispanic voters and other minorities.
A White House spokesman did not immediately respond to a request for comment Friday on which candidate Trump prefers in the primary.
They have a top-tier candidate in Rep. Kyrsten Sinema.
The primary is not until August 28.
"It kind of eases her path to the nomination", said Jennifer Duffy, who analyzes Senate races for the Cook Political Report in Washington.