BATTLEGROUND SERIES: Arizona's 11 electoral votes hinge on key swing county Biden won by a hair in 2020

MARICOPA COUNTY, Ariz. – Arizona is expected to be one of the most closely watched and highly competitive swing states in the upcoming presidential election and the state’s largest county will play a critical role in deciding who wins that state and ultimately the White House.

Maricopa County, which surrounds Phoenix in south central Arizona and is home to over 4.5 million people, is widely considered one of the key battleground counties in the United States due to its diverse political breakdown and will deliver 11 crucial electoral votes to either former President Trump or Vice President Kamala Harris.

"Maricopa County is our largest and most populous county in Arizona," Arizona GOP Chairwoman Gina Swoboda told Fox News Digital. "It contains over 60% of our voters statewide. It's about a third Democrat, a third Republican, and a third Independent. That fluctuates a bit. But essentially, we're a third, a third, a third."

"We have what I would call a dense urban core in Phoenix. And then we have suburbs and it's growing. It's consistently one of the highest growing counties in the United States. It's a diverse county just because of the makeup, we've got urban and then we've got the suburbs and then we have what were kind of little, little towns becoming cities very rapidly. So when you have that kind of growth, that puts a lot of pressure on a community and because it's 60% of the vote of the state, it gets a lot of attention."

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Swoboda told Fox News Digital that if you’re looking to run for office in Maricopa County you’ve got a "broad swath of the electorate" and you "have to speak to their issues."

Those key issues during this election cycle, according to Swoboda, are the economy and immigration. 

"Inflation is number one and when we say inflation in Arizona, we're one of the hardest hit states in the country for our prices going up," Swoboda said. "But part of that is affordable housing. And that's a huge issue in the state of Arizona, particularly in rapidly growing Maricopa."

President Joe Biden won the state of Arizona by less than 1 half of 1 percent in the 2020 election and the results in Maricopa County were also slim with Biden beating former President Trump by 2 %.

The Harris-Walz campaign has been active in the county over the last few months and the Arizona campaign team told Fox News Digital that they have knocked on 90,000 doors, made over 1.7 million phone calls, and have 15,000 volunteers that have completed a shift in the county.

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"Vice President Harris, Governor Walz, Second Gentleman Emhoff, and Minnesota First Lady Gwen Walz all visited Arizona in September," the campaign said. "Recently, Vice President Harris visited Douglas, Arizona to tout her policies to keep Arizona's border secure, marking her eighth visit to Arizona this year."

Polling has increasingly shown that Trump leads Harris with low propensity voters which has become an increased focus in the Trump ground game. The same is true in Arizona, specifically Maricopa County, where Turning Point Action, which has taken the lead in organizing Trump’s GOTV efforts, has launched programs like "Commit 100" and "Chase the Vote" to mobilize those voters.

A spokesperson for Turning Point Action told Fox News Digital that it is actively targeting 400,000 low propensity voters in Arizona and that Republican voter registration efforts in Arizona over the last two years has "put the state in a very difficult mathematical spot for Democrats."

A spokesperson for the RNC told Fox News Digital that Republicans have "doubled" the GOP voter registration advantage in Arizona since 2020 and that the RNC has almost a dozen offices across the state as part of its Trump Force 47 initiative to "meet voters where they are."

Nationwide, immigration is one of the most important issues to voters according to the polls and that's no different in Arizona where voters who spoke to Fox News Digital said immigration is a top concern despite differing opinions on which candidate would best handle the unfolding crisis.

"We have to have swifter incarceration at the border," Mary from Phoenix told Fox News Digital. "And if there's a suspicion that they're going to commit a crime, lock them up."

Mary said that it was "infuriating" that the recent bipartisan border deal died in Congress and said that if Harris is elected, "She will get it signed."

Nick from Sun City West told Fox News Digital that Harris' immigration policy has been "dismal at best."

"Control the border," he said. "At least keep the border safe. Keep people from being able to get in that aren't supposed to be able to come in unless they come in through the regular normal channels."

Trump holds a razor-thin two-point edge over Harris in battleground Arizona, according to a recent public opinion poll.

Fueling the former president's margin appears to be support from voters age 50 and over. Trump stands at 49% among likely voters in Arizona, with Harris at 47%, according to an AARP poll conducted Sept. 24-Oct. 1 and released on Tuesday. According to the survey, Green Party candidate Jill Stein grabs 1% support, with 3% undecided.
 

"In some ways, it's like a state of its own because 65, 68% of our entire state population in Arizona resides in Maricopa County," Arizona GOP Senate candidate Kari Lake told Fox News Digital. "It's one of those mega counties. I frankly also think it's a mega county, but it's a mega county. And so it's a really important county. What happens in Maricopa County can affect the entire country and really the entire world, because we know whatever way Maricopa County can take the whole country that way, because it's so massive, it can take the whole state that way. And so it's an important county."

Fox News Digital's Paul Steinhauser and Hannah Ray Lambert contributed to this report