The doctor and former Arizona state senator, who failed to unseat Sen. John McCain in a 2016 Senate primary, is now taking on Sen. Jeff Flake in 2018. Now, all eyes are on the red state as President Donald Trump, who appeared to encourage Ward by name in a tweet last week, heads there Tuesday for a rally in Phoenix.

Still, there are two other Republicans -- State treasurer Jeff DeWit and former state party chairman Robert Graham -- who could still enter the race and are broadly regarded as standing better chances of defeating Flake should they jump in the race.

Here's a look at Ward's political past:

'Arizona deserves better'

Ward has said she aspires to be the "conservative voice" in the Senate.

"I have been selected by the people of our state and the people of our country, who are looking for a conservative voice in the United States Senate," she told "Fox & Friends" Monday. "And unfortunately for us in Arizona, we don't have a conservative Republican senator. We don't have a senator who supports the President at all. And so 2018, it's time for a change."

Ward told Fox she believes "the biggest contrast" between Flake and her is that the incumbent Republican "believes in open borders and amnesty." Where as Ward said she believes in "building the wall and stopping illegal immigration."

She also touched on health care, calling it "appalling" that the House, Senate and White House "couldn't get the job done for the American people."

"People in Arizona are suffering with high deductibles, and skyrocketing premiums. and they can't access high quality cost-effective health care," she said. "I have a track record in the Arizona state Senate of being very conservative. and doing what I say. I'm a person of action, not a person of talk. And so I look forward to getting there and getting the job done we all want done."

On Monday, Ward released a new campaign online web video called "Arizona deserves better," which will be "distributed digitally across Arizona this week, including in the downtown Phoenix region via digital geographic targeting prior to the President's campaign rally on Tuesday evening," her campaign said in a statement.

Critical of McCain

But the publicity may not help, as Ward has been controversial in the past.

While in the Arizona state legislature, she tried to outlaw enforcement of federal gun laws in Arizona.

In 2016, she did an interview with Alex Jones , a notable far-right radio show host and conspiracy theorist who believes the September 11 attacks were an inside government job.

Last year, she made headlines after calling McCain "old" and "weak." More recently, in July, she sparked social media backlash after she said McCain should step aside as quickly as possible following the news this week of his brain cancer diagnosis.

"I hope that Senator McCain is going to look long and hard at this, that his family and his advisers are going to look at this, and they're going to advise him to step away as quickly as possible," she said on Indiana radio WOWO 1190 AM . "So that the business of the country and the business of Arizona being represented at the federal level can move forward."

Tweet of approval and big money coming in

Though she has not been favored by many, Trump appears to have thrown support behind her -- at least via Twitter.

"Great to see that Dr. Kelli Ward is running against Flake Jeff Flake, who is WEAK on borders, crime and a non-factor in Senate. He's toxic!" Trump tweeted last week.

Great to see that Dr. Kelli Ward is running against Flake Jeff Flake, who is WEAK on borders, crime and a non-factor in Senate. He's toxic! — Donald J. Trump (@realDonaldTrump) August 17, 2017

Although Flake has generally sided with Trump and the Republicans on Senate votes, he has been vocal about his criticism of the President. In his recent book , "Conscience of a Conservative," Flake compared Trump's campaign to a "late-night infomercial" with an agenda that is "free of significant thought."

Ward -- a longtime proponent of Trump -- has expressed enthusiasm about Trump's positive words.

"President Trump doesn't support Jeff Flake for good reason -- he has opposed and insulted him for the past two years and that's a huge liability for Arizona," Ward said in a statement Monday.

Her campaign has received both manpower and money from Trump supporters.

Eric Beach and Brent Lowder, of Great America PAC, which were supportive of Trump, are on Ward's campaign team.

"They were committed to electing Donald Trump to be the president and now they are committed to helping me retire Jeff Flake," Ward said of Beach and Lowder on "Fox & Friends."

Robert Mercer, one of the President's largest donors, sent a $300,000 contribution to a PAC that supports Ward's candidacy.

Meanwhile, Flake deflected reporters' questions on Monday about Trump's tweets that he is "a non-factor in the Senate" and "toxic!"

"I don't worry about it at all," Flake said.