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Arizona’s status as a swing state was cemented the last two election cycles when President Biden won here in 2020 and Democrats swept key statewide races, including a U.S. Senate seat, in 2022.

But Democrats’ share of the electorate is down under Biden — Republicans now hold a nearly 260,000-person advantage among registered voters in Arizona, and hope to use that advantage to reclaim the state for former President Donald Trump, who lost by less than 11,000 votes four years ago.

And control of Congress could run through Arizona, with competitive House and Senate races that will be set after voting closes in today’s state primaries.

Here are some of the key races to watch:

Last minute dual Trump endorsements

Former President Donald Trump appears to be hedging his bets to ensure he’s backed winning candidates who will support his cause on ballots in November.

Trump took to Truth Social on Saturday night to endorse venture capitalist Blake Masters, who lost the U.S. Senate race in Arizona in 2022 to Democrat Mark Kelly, in the crowded GOP primary to replace outgoing Congresswoman Debbie Lesko in Congressional District 8.

But Trump had already pledged his support in that race to Abe Hamadeh, who narrowly lost a race for Arizona attorney general in 2022 and, like Trump, has promoted baseless claims of election fraud.

On social media Saturday evening, Trump said voters in the West Valley suburbs of Phoenix have “two spectacular America First Candidates” to choose from.

“I’m pleased to announce that both Blake Masters and Abe Hamadeh have my Complete and Total Endorsement,” Trump wrote.

The 11th hour dual endorsement of both candidates likely ensures Trump has picked a winner in CD8 — public polling has consistently ranked Masters and Hamadeh neck-and-neck in what’s become a bitter race defined by each candidates’ fealty to Trump.

But it’s unclear how voters who had planned to cast a ballot for whoever Trump supports will now decide between the two.

Hamadeh, who’s echoed Trump’s false claims of election fraud by consistently filing failed legal challenges to his own 2022 election loss, could previously boast the exclusive endorsement of Trump, as well as that of Trump ally Kari Lake, a failed gubernatorial candidate in 2022 now running for U.S. Senate with Trump’s blessing.

Now Masters, who’s spent much of the campaign broadcasting his loyalty to Trump — as well as the former president’s endorsement of his failed U.S. Senate bid two years ago — can boast the same, as well as the endorsement of Sen. JD Vance of Ohio, who backed Masters well before Vance was tapped as Trump’s vice presidential running mate.

The race that could help determine control of the Senate

Whichever Trump acolyte wins in CD8 is likely assured victory in November— the district heavily favors Republican candidates, and will be considered a safe seat for a GOP incumbent in elections to come.

But Trump’s endorsement will be tested elsewhere on the ballot.

Lake, another Trump ally who refuses to accept her 2022 defeat to Democrat Katie Hobbs in the race for Arizona governor, has been considered the frontrunner for the GOP nomination for U.S. Senate ever since she burst into the race with Trump’s endorsement last fall.

But some Republicans fear a repeat for Lake in 2024, and yet another statewide race lost by Republicans in this newly minted swing state.

If she secures the nomination, Lake will face Congressman Ruben Gallego, who’s running unopposed for the Democratic nomination. Lake has routinely polled behind Gallego, trailing well behind Trump’s more favorable numbers in Arizona as she’s been dogged by her continued election denialism and shifting positions on abortion, an issue that may literally be on the ballot this fall — more than 800,000 Arizona voters signed onto an initiative that would enshrine the right to an abortion in the state constitution.

Lake’s perceived weakness as the GOP candidate in the general election has led some to favor her longshot primary opponent, Pinal County Sheriff Mark Lamb.

Last week, Arizona GOP mega donor Randy Kendrick, the wife of Arizona Diamondbacks owner Ken Kendrick, sent an email to her allies claiming Lake “cannot win” in November and is a lost cause.

Democratic hopes to pick up a House seat

As for Democrats, voters must nominate a candidate to replace Gallego, who’s abandoning a safe seat in the House to run for Senate.

Polling shows a two-person race between former Arizona state Sen. Raquel Teran and former Phoenix city councilmember Yassamin Ansari, each of whom would mark a first if elected — Teran would be the first Latina sent to Congress in Arizona, while Ansari would be the first Democratic Iranian American to serve in Congress.

That race in Arizona’s 3rd Congressional District has drawn significant outside interest from Republican donors, cryptocurrency forces and even the Winklevoss twins of Facebook fame.

The nearby race in CD1 has also attracted a wealth of attention, and a wealth of Democratic candidates vying for the chance to challenge incumbent Congressman David Schweikert.

Schweikert is considered a vulnerable Republican — his margin of victory of Democratic challengers has shrunk considerably in recent years, and the six candidates running for the Democratic nomination are pitching themselves as the right candidate to finally defeat Schweikert in November.

But the candidates have struggled to distinguish themselves from one another, and polls show no clear favorite in the race.