GILBERT, Ariz. (AP) -- Republican Senate candidate Martha McSally had a boost from GOP stalwart Mitt Romney as the two urged energized supporters at an Arizona rally Friday to help her win a "dead heat" race.
"This is such a consequential election for us up and down the ballot," McSally said to a cheering crowd in the Phoenix suburb of Gilbert. "This Senate race is literally the firewall to make sure we keep and grow the Senate majority."
Branding her opponent as an anti-military liberal, the congresswoman is facing Democrat Kyrsten Sinema for the seat being vacated by Republican Sen. Jeff Flake. Both women left their seats in the U.S. House to seek the Senate post.
>>VIDEO: McSally campaign rally in Gilbert
A victory will only happen if her supporters spread the word to either vote early or at the polls, McSally said.
"It's so important that you're engaged but we got to get out there," she said. "We got to get out there to our friends and family, on social media, people in our neighborhoods, people in our workplace. This has come down to get-out-the-vote, right?"
Romney, a heavy favorite in Utah's Senate race, introduced McSally. The Gilbert area is heavily Mormon, and Romney is arguably the nation's best-known member of the Salt Lake City-based faith.
The former GOP presidential nominee highlighted McSally's reputation as the first U.S. female fighter pilot and her various combat missions.
"This is the kind of person Arizona deserves and the country needs," Romney said. "I'm hoping when I get elected to the Senate...we are able to work together to take on some big challenges."
Several hundred people stood inside an auditorium for the 20-minute rally. Many wore red or blue T-shirts with either pro-McSally or pro-Donald Trump messages while waving miniature U.S. flags. Veterans in the crowd were applauding McSally's military background.
Some in attendance said they support her because she would work with President Trump and help keep the Republicans' hold on the Senate majority.
"She doesn't flip-flop like the other candidate," said Sadiq Ahmed, a registered independent who voted for both Barack Obama and Trump. "At this time, it's better for America to support Republicans."
Both McSally and Romney have mostly supported Trump. But neither invoked his name during the gathering.
McSally did mention Sinema several times, drawing resounding boos from the crowd. McSally focused on Sinema's past anti-war protests.
"Not only was she protesting our troops in a pink tutu...she certainly has a right to do that but is that who we want to be our next senator?"
The rally comes just days after early voting began in Arizona for the Nov. 6 election.
Sinema, who was raised Mormon, is a moderate, three-term congresswoman representing parts of metro Phoenix. She began her political career as a Green Party activist and now casts herself as an independent.
She has built a moderate record in Congress, often supporting Republican bills.
McSally is a one-time moderate who is now in her second term representing parts of southern Arizona.
The GOP has worked hard to cast Sinema as a liberal who is too far left for Arizona. McSally also says Sinema, a former rape crisis counselor, was soft on punishment for child molesters.
Sinema's campaign said the attacks are a sign of an increasingly desperate McSally camp.
Rally with Gov. Mitt Romney
Oct. 12, 2:30 p.m. - 4:30 p.m.
The Falls Event Center
4635 E. Baseline Rd.
Gilbert, AZ 852534
AP writer Bob Christie in Phoenix contributed to this story.