Donald Trump visits Phoenix, June 2016

Trump supporters walks out after listening to presumptive Republican presidential nominee, Donald Trump speech at the Veterans Memorial Coliseum in Phoenix on June 18, 2016.

A spattering of empty seats is seen during a Presidential rally for Donald Trump on Saturday, June 18, 2016 at the Veterans Memorial Coliseum in Phoenix, Ariz.

Rory Sauter, 25 from Tempe, shows his support for Donald Trump while presumptive Republican presidential nominee, Donald Trump speaks at the Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Protestors from both sides argue while presumptive Republican presidential nominee, Donald Trump speaks at the Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Trump supporter Paul (didn't gave his last name) argue with protestors while presumptive Republican presidential nominee, Donald Trump speaks at the Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Protestors from both sides argue while presumptive Republican presidential nominee, Donald Trump speaks at the Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Protestors from both sides argue while presumptive Republican presidential nominee, Donald Trump speaks at the Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Trump supporters guards against protestors while presumptive Republican presidential nominee, Donald Trump speaks at the Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Protestors from both sides argue while presumptive Republican presidential nominee, Donald Trump speaks at the Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Donald Trump supporter Zack Fisher yells at protesters outside a rally for the presumptive Republican presidential nominee at Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Rory Sauter, 25, of Tempe shows his support for Donald Trump in front of protesters outside a rally for the presumptive Republican presidential nominee at Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Donald Trump thanks Phoenix police officers as he prepares to board his private plane at Phoenix Sky Harbor International Airport on June 18, 2016.

Donald Trump points at state Treasurer Jeff DeWit (giving a thumbs up) before boarding his plane to leave Phoenix on June 18, 2016.

Donald Trump gives two thumbs up as he greets police officers before boarding his plane to leave Phoenix on June 18, 2016.

Jorge Soria (left) and Steve Kollmeyer argue after a rally for Donald Trump at Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Dai Dawson of Phoenix protests outside a rally for presumptive Republican presidential nominee Donald Trump at Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Donald Trump held a rally June 18, 2016 at the Veterans Memorial Coliseum in Phoenix.

An audience gathers in a partially full auditorium to listen to Donald Trump speak during a Presidential rally for Donald Trump on Saturday, June 18, 2016 at the Veterans Memorial Coliseum in Phoenix, Ariz.

Donald Trump shakes hands and signs autographs during a Presidential rally for Donald Trump on Saturday, June 18, 2016 at the Veterans Memorial Coliseum in Phoenix, Ariz.

Donald Trump speaks during a Presidential rally for himself on Saturday, June 18, 2016 at the Veterans Memorial Coliseum in Phoenix, Ariz.

Donald Trump speaks during a Presidential rally for himself on Saturday, June 18, 2016 at the Veterans Memorial Coliseum in Phoenix, Ariz.

Donald Trump speaks during a Presidential rally for himself on Saturday, June 18, 2016 at the Veterans Memorial Coliseum in Phoenix, Ariz.

Donald Trump signs autographs after his Phoenix rally June 18, 2016.

Donald Trump mingles with the crowd after a rally June 18, 2016, at the Veterans Memorial Coliseum in Phoenix.

An audience gathers in a partially full auditorium to listen to Donald Trump speak during a Presidential rally for Donald Trump on Saturday, June 18, 2016 at the Veterans Memorial Coliseum in Phoenix, Ariz.

Donald Trump shakes hands and signs autographs after a rally June 18, 2016, at the Veterans Memorial Coliseum in Phoenix.

Donald Trump receives a kiss from Diana Brest of Phoenix after his rally June 18, 2016, at Veterans Memorial Coliseum in Phoenix. Brest waited in line 14 hours to attend the event.

Donald Trump shakes hands and signs autographs after a campaign speech June 18, 2016, at Veterans Memorial Coliseum in Phoenix.

Donald Trump speaks during a Presidential rally for himself on Saturday, June 18, 2016 at the Veterans Memorial Coliseum in Phoenix, Ariz.

Donald Trump shakes hands and signs autographs during a Presidential rally for Donald Trump on Saturday, June 18, 2016 at the Veterans Memorial Coliseum in Phoenix, Ariz.

Donald Trump shakes hands and signs autographs during a Presidential rally for Donald Trump on Saturday, June 18, 2016 at the Veterans Memorial Coliseum in Phoenix, Ariz.

Donald Trump speaks during a rally June 18, 2016, at the Veterans Memorial Coliseum in Phoenix.

Buttons from the Donald Trump rally in Phoenix on June 18, 2016.

A Donald Trump imitator poses during a rally in Phoenix on June 18, 2016

Donald Trump exits the stage after a rally in Phoenix June 16, 2016.

Donald Trump speaks to supporters in Phoenix at Veterans Memorial Coliseum on June 18, 2016.

OO OA spattering of empty seats is seen during a Presidential rally for Donald Trump on Saturday, June 18, 2016 at the Veterans Memorial Coliseum in Phoenix, Ariz.

A spattering of empty seats is seen during a Presidential rally for Donald Trump on Saturday, June 18, 2016 at the Veterans Memorial Coliseum in Phoenix, Ariz.

Donald Trump enters a campaign rally in Phoenix on June 18, 2016.

Men carrying guns -- one a Donald Trump backer, the other a critic -- argue outside Donald Trump's rally in Phoenix on June 18, 2016.

Philip Ring holds a sign slamming Donald Trump's hair outside a rally for presumptive Republican presidential nominee at Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Donald Trump speaks at a campaign rally at Veterans Memorial Coliseum in Phoenix on June 18, 2016.

A spattering of empty seats is seen during a Presidential rally for Donald Trump on Saturday, June 18, 2016 at the Veterans Memorial Coliseum in Phoenix, Ariz.

Former Gov. Jan Brewer draws applause at the Donald Trump rally at Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Trump supporters hype up the crowd prior to a presidential rally for Donald Trump on Saturday, June 18, 2016, at the Veterans Memorial Coliseum in Phoenix.

Sheriff Joe Arpaio wears a "Make America Great Again" hat during a rally for Donald Trump on Saturday, June 18, 2016, at Veterans Memorial Coliseum in Phoenix.

Trump supporters catch free hats saying "Make America Great Again" during a rally for presidential candidate Donald Trump on Saturday, June 18, 2016, in Phoenix.

Mike Roberts (right) tries to get his message across outside a rally for presumptive Republican presidential nominee Donald Trump at Veterans Memorial Coliseum in Phoenix, Ariz. June 18, 2016.

Mike Roberts (right) tries to get his anti-Trump message across to Paul (would not give last name) outside a rally at Veterans Memorial Coliseum for the presumptive Republican presidential nominee in Phoenix, Ariz. June 18, 2016.

Sumayyah Dawud, of Phoenix, protests outside a rally for presumptive Republican presidential nominee, Donald Trump, at the Veterans Memorial Coliseum in Phoenix on June 18, 2016.

A Donald Trump impersonator stands outside the Trump rally at Veterans Memorial Coliseum in Phoenix on June 18, 2016

A pair of Trump protesters demonstrate outside Veterans Memorial Coliseum on June 18, 2016.

Donald Trump arrives at the Swift Aviation landing strip on Old Tower Road in Phoenix on June 18, 2016.

Marina and Jeff DeWit, the state treasurer, wait for Donald Trump to arrive at the Swift Aviation landing strip in Phoenix on June 18, 2016

A woman in a "U.S. Border Patrol" hat carries a "Don't Tread on Me" flag below the American flag.

William Robles, 47, wore a donkey costume outside of a Donald Trump rally in Phoenix on June 18, 2016, because, he said, "Trump is a donkey." The temperature outside was 106 degrees.

A Donald Trump supporter engages in a heated argument with a foe outside Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Trump supporters gather in Veterans Memorial Coliseum on June 18, 2016.

Trump supporters stream in to hear presumptive Republican presidential nominee Donald Trump speak at Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Code Pink demonstrators Edwina Vogan and Virginia Hauflaire silently protest outside the Donald Trump rally in Phoenix on June 18, 2016.

Bikers head to the rally for presumptive Republican presidential nominee Donald Trump at the Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Maricopa County Sheriff Joe Arpaio speaks to attendees at a rally for Donald Trump on June 18, 2016, at Veterans Memorial Coliseum in Phoenix.

Maricopa County Sheriff Joe Arpaio arrives at Veterans Memorial Coliseum before a Donald Trump rally on June 18, 2016.

DPS officers secure the area for Republican presidential nominee Donald Trump at Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Steven Ramierz (left) and Diana Brest listen to a Secret Service agent on June 18, 2016. They were the first in line for Donald Trump's rally at Veterans Memorial Coliseum.

Mikey Osborn, 7, rests from the heat with his parents while they wait in line to watch presumptive Republican presidential nominee Donald Trump at Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Long lines formed outside Veterans Memorial Coliseum as people waited to see presumptive Republican presidential nominee Donald Trump on June 18, 2016.

A spattering of empty seats is seen during a Presidential rally for Donald Trump on Saturday, June 18, 2016 at the Veterans Memorial Coliseum in Phoenix, Ariz.

Biker Steven Shepard, 66, says he's trying to keep the peace as he heads to the Donald Trump rally at Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Joe Foran, 61, of Mesa, shades himself from the sun outside the Donald Trump rally in Phoenix on June 18, 2016.

Steve and Selena Beverley of Surprise (left) and Esther Deschamps and Neil Balsino of Tucson wait in line outside Veterans Memorial Coliseum before a rally for presumptive Republican presidential nominee Donald Trump.

Linda Sanchez waits in line with her son, Christian, of Gilbert, before a rally for presumptive Republican presidential nominee Donald Trump at Veterans Memorial Coliseum in Phoenix on June 18, 2016.

Donald Trump's private jet landed in Phoenix just before 2 p.m. June 18, 2016, in advance of a rally.

Bryan Sanders, who said he was beaten at a Donald Trump rally in Tucson, arrives at a Trump rally in Phoenix on June 18, 2016.

Nick Davis of Las Vegas was selling buttons for $2 each at the Donald Trump rally in Phoenix on June 18, 2016. People wanted them for free.

William Robles, 47, of Guadalupe cools off while protesting in a donkey costume at a rally against presumptive Republican presidential nominee Donald Trump at Encanto Park in Phoenix on June 18, 2016.

Jim Perrin of Phoenix gets some water before a rally for presumptive GOP presidential nominee Donald Trump at Veterans Memorial Coliseum in Phoenix on June 18, 2016. Perrin is one of the Riders attending the rally to help keep the peace.

Signs await supporters at the Donald Trump event in Phoenix at Veterans Memorial Coliseum.

Monica Miramontes, 17, of Mesa holds a sign during an anti-Trump rally at Encanto Park in Phoenix on June 18, 2016.

A supporter sports Trump regalia at a rally in Phoenix on June 18, 2016.

Riders USA showed up at the Donald Trump rally in big numbers, saying members planned to protect First Amendment rights.

At an anti-Trump peace rally, attendees raise a Donald Trump balloon in KKK garb that says: "Make America Hate Again."

Donald Trump campaign buttons are for sale at the Trump Shop just outside the Veterans Memorial Coliseum in Phoenix on June 18, 2016.