Presidential candidate Ted Cruz speaking at a campaign rally on March 19, 2016 | George Frey/Getty Images Is Cruz already too late to stop Trump? Arizona’s primary is Tuesday, but more than half the ballots have already been cast — including for candidates who’ve left the race.

By the time Ted Cruz arrived Friday at the tiny border town of Douglas for his first Arizona event of 2016, he was already too late for the hundreds of thousands of Republicans who had already voted.

Election day is still two days away in Arizona but well more than half of Republicans expected to vote in the state’s Tuesday primary have already cast their ballots — complicating Cruz's attempts overtake Donald Trump as both make a late push for the state’s lucrative, winner-take-all prize of 58 delegates.

“A candidate cannot win Arizona if they don’t do well in early balloting,” said Nathan Sproul, an Arizona Republican strategist who had served as co-chair for Marco Rubio’s campaign in the state.

Arizona has among the most robust early-voting programs in the country. In Maricopa, the state’s largest county, early voters in 2016 comprise already nearly 90 percent of the county’s total GOP turnout four years ago.

Cruz’s most recent Arizona ad tries to tap into voters’ fears of crimes committed by undocumented people crossing the border.

This raft of early voting represents a particular challenge for Cruz, whose team acknowledges he is likely climbing out of a hole, even though the campaign first put an Arizona team in place last September. John Kasich has all but written off the state, neither visiting nor investing resources, but the Cruz campaign is not getting a true head-to-head battle with Trump: Many votes were cast before the race consolidated, including for Cruz rivals who are no longer in the race.

In fact, veteran Arizona strategists and the Cruz campaign estimate as much as half the vote was cast even before Marco Rubio dropped out on March 15.

“Trump would have a natural lead because it’s a fragmented field,” said Cruz campaign manager Jeff Roe of the early vote on the night of the March 15 elections.

Constantin Querard, Cruz’s Arizona state director, noted they had gained momentum since Rubio dropped out but added, “We don’t know how much of a deficit we have to overcome.”

The outcome in Arizona is critical, not just for its bounty of delegates but for its ability to reset the tenor and trajectory of the Republican nominating contest for almost a month. Arizona and Utah, where Cruz appears favored, vote on Tuesday but the Republican race slows to a crawl after that, with only a single other state voting in the following four weeks. That means either a Trump or Cruz sweep would linger in the media longer than any prior primaries.

Underscoring the urgency, Trump held rallies in the state's two largest cities on Saturday, as he, like Cruz, turns his attention to the state late.

Public polling in Arizona has been scant, though Trump led Cruz by double digits in the two public surveys released this month. Internal polling from a Cruz super PAC, obtained by POLITICO, showed Cruz and Trump in a dead heat, even in a four-candidate race. In a survey conducted March 7-8, Trump led 25.5 percent to 23.8 percent, with Rubio and Kasich fair behind with 10 and 11 percent, respectively, and nearly 30 percent of voters undecided.

"We have more of an election month than an election day,” Querard said. “You have to pace yourself but you have to go full speed as long as possible.”

He added of the pressure emanating from Cruz’s Houston headquarters: “They’re kicking the stirrups pretty hard.”

Arizonans are already voting at a record-setting pace. In Maricopa County, which includes the Phoenix area and accounts for 60 percent of Arizona’s total population, 249,702 of the 708,941 registered Republicans had returned their ballots as of Friday. Total turnout was about 280,000 in 2012. In Pima County, Arizona’s second largest and home to Tucson, more than 60,000 voters had cast ballots by Friday — roughly 85 percent of the 2012 turnout.

Yet none of the campaigns had registered much activity until only days ago. Cruz’s campaign was the first to hit the airwaves, buying ads starting on March 12. One of his super PACs joined in recent days, as Trump has opened his wallet to buy television ads, as well.

Cruz’s most recent Arizona ad tries to tap into voters’ fears of crimes committed by undocumented people crossing the border. It features the wrenching testimony of a father who says his son’s killing at the hands of an illegal immigrant was “completely preventable.”“I trust Ted Cruz,” the father says.

Immigration is expected to loom large in a state where the topic has long dominated Republican politics. Trump, who has the support of controversial Sheriff Joe Arpaio and former Republican Gov. Jan Brewer, has made building a wall on the southern border his signature issue.

Kasich, though, mostly has been a non-presence and non-factor.

Last week, the Cruz campaign pushed back after POLITICO reported that he would need to win Arizona in an outline of Cruz’s internal view of the path to getting 1,237 delegates to secure the nomination. To reporters on March 15, Roe compared the Arizona dynamics to Louisiana, where they “won overwhelmingly” among election day voters but fell just short of overcoming Trump’s led among early balloting.

The Cruz campaign hopes such a late surge could be portrayed as a victory, even if he loses all 58 of Arizona’s delegates. A memo from Cruz’s team on delegate strategy on March 15 said a multi-candidate field in Arizona would effectively allow Trump to win.

Kasich, though, mostly has been a non-presence and non-factor. “If he has a state chairman, I don’t even know who it is,” Querard said. (On Friday, after Querard spoke with POLITICO, Kasich announced his Arizona leadership team.)

Cruz’s campaign does have a program identifying likely supporters and directing volunteers to make calls and and knock on their doors. “There isn’t any other campaign that’s doing that level of engagement in Arizona,” said Sean Noble, an Arizona Republican strategist who previously supported Rubio. “I would have to put a slight advantage to Cruz because he has some presence here.”

Sproul, the other Arizona strategist, got his ballot early and has held it for weeks to see if any campaigns would contact him. None did. “I would have expected some of the campaigns to have at least done a few mail pieces, phone calls, a little bit of outreach,” he said. “It’s been remarkably quiet.”

Katie Glueck contributed.