Reports of a potential merger between United Airlines and American Airlines are evoking painful memories of past megadeals that left the Valley without a major hub or airline headquarters.

Why it matters: Major airline mergers often result in higher fares for all passengers, but they also can severely impact service at certain airports as the new company consolidates routes.

• And Sky Harbor would be an obvious place to cut back if a United-American merger came to fruition, industry experts told Axios.

Driving the news: United CEO Scott Kirby pitched the merger idea to President Trump in a February meeting, Reuters and others reported this week.

• United declined to comment to Axios and American did not respond.

Threat level: Sky Harbor's status as an American hub could be on the chopping block because United has a much larger and established hub at nearby Denver International Airport, per Henry Harteveldt, president and airline industry analyst at Atmosphere Research Group.

• Sky Harbor is American's fifth largest hub and largely exists as a holdover hub from when American merged with Tempe-based U.S. Airways, he told us.

By the numbers: American is Sky Harbor's largest carrier, operating approximately 40% of flights. United is responsible for about 6%, airport spokesperson Jon Brodsky told Axios.

The big picture: The Valley is understandably leery of airline mergers.

• Homegrown airline America West in 2005 acquired the bankrupt U.S. Airways, adopted its name and moved the national airline's headquarters to the Valley.
• But in 2013, American Airlines acquired U.S. Airways. The companies at the time promised to maintain a hub and corporate presence in Phoenix, but U.S. Airways' C-suite quickly relocated to Dallas and its downtown Tempe offices shuttered.

Reality check: Harteveldt is extremely skeptical that a merger of two of the big four airlines will ever actually happen, even under Trump's very pro-business administration.

• Combining United and American would place about a third of all air travel under one company, which would face intense backlash from federal antitrust regulators and state prosecutors, he said.

What we're watching

It's Tax Day, and if you've been waiting for Gov. Hobbs and GOP lawmakers to sort out their tax conformity fight before you file, you're out of luck.

Why it matters: Some taxpayers who itemize may need to file amended returns later this year, depending on whether the governor and Legislature make changes to the tax code.

State of play: The Arizona Department of Revenue says on its website that the agency will provide guidance to impacted taxpayers.

• People who file amended returns won't be subject to any fines or penalties, provided they meet the Oct. 15, 2027 deadline.
• Per ADOR, people won't have to re-file if they take the standard deduction (that's most Arizonans) and don't plan to claim deductions for overtime pay, tips, Qualified Vehicle Loan Interest or the $6,000 senior deduction.

Yes, but: If the tax code for 2025 is changed to match ADOR's forms, which include all of last year's federal changes, no one will have to file amended returns, Sen. J.D. Mesnard (R-Chandler) noted to Axios.

• Mesnard, who chairs the Senate Finance Committee, said Republicans won't agree to anything that makes people file amended returns, which would require full conformity with federal law for 2025.

Catch up quick: Hobbs and the Republican majority have fought throughout the session about how to conform state tax code to federal changes made last year by President Trump's One Big Beautiful Bill Act.

• Hobbs demanded that lawmakers pass a partial conformity law that she dubbed her Middle Class Tax Cuts bill, and said she'd negotiate other tax changes with Republicans as part of the state budget.
• She vetoed two conformity bills the Legislature sent her.

Don't forget Tax Day

🗳️ Maricopa County Recorder Justin Heap discussed election records and litigation with the Department of Justice last year as the feds sought Arizona voters rolls. (Votebeat)

🏢 ICE signed a lease for office space in Flagstaff, per city officials. (AZcentral)

🥩 Perry's Steakhouse & Grille, a Texas-based restaurant, will open its first Arizona location in Gilbert in June. (ABC15)

🎾 Mesa Padel Club will have its grand opening on Saturday. (KTAR)

The Phoenix Suns blew an 11-point lead in a play-in game against Portland and have one more chance to break into the first round of the NBA postseason.

Driving the news: The Trail Blazers rallied late in the fourth quarter to hand the Suns a 114-110 loss last night at Mortgage Matchup Center in Phoenix and earn the No. 7 seed in the Western Conference.

• Portland's Deni Avdija hit a layup to give the Blazers the lead with 16 seconds left, capping a 41-point night for him.
• Jalen Green, who led the Suns with 35 points, missed what would've been a game-winning three-pointer as the fourth quarter came to an end.
• The Blazers will play the second-seeded San Antonio Spurs in the first round.

What's next: Phoenix will play the winner of tonight's play-in game between the Los Angeles Clippers and Golden State Warriors for the eighth seed in the West.

• The winner will face the defending champion Oklahoma City Thunder, the NBA's top team, in the first round.

Let's go, Suns!