President Trump speaks to supporters at Mesa rally

MESA, Ariz. (KSAZ/AP) -- Friday was a busy day for President Donald Trump, as he attended several events in the Valley, before attending his big rally in Mesa.

Trump has visited Arizona about 10 times, since his presidential campaign first began a few years ago. In Mesa, where the rally was planned to be held at a hanger located within the Phoenix-Mesa Gateway Airport, supporters have been gathering since earlier Friday afternoon.

President Trump is in Arizona to help stump for Rep. Martha McSally. She and Democratic Rep. Kyrsten Sinema are vying for the seat of Republican Sen. Jeff Flake, who is retiring. McSally was a Trump critic in 2016 and represents a Tucson district that voted for Democrat Hillary Clinton. She's now embraced the president and hopes his visit to Arizona helps unites Republicans against Sinema. 

Trump says McSally, who is a former Air Force colonel and combat fighter pilot, is "brilliant and brave" and has a "very, very strange opponent." 

Trump didn't say why he thought Sinema was "strange."

At the rally, Trump said Democrats are to blame for America's immigration problems.

He says the new platform of the Democratic Party is "Radical socialism and open borders." Trump says the Democrats are opening "inviting millions of illegal aliens to break our laws, violate our borders and overwhelm our nation."

Trump also pledged to end what is called "chain migration" where one person immigrates and then brings their extended family into the country.

The Associated Press is reporting that Trump's comments about "radical socialism" and "open borders" are not accurate reflections of Democratic positions, and his comments about migrants breaking the law and being "hardened criminals" do not provide a correct picture of the immigrant population.

According to the AP, several studies from social scientists and the libertarian think tank Cato Institute have shown people here illegally are less likely to commit crime than U.S. citizens, and legal immigrants are even less likely to do so.

Meanwhile, many of the people who were at the rally had been waiting to get into the rally site, since Friday morning.

"We're here to support the greatest President of the United States," said one supporter. "We were at the first rally in Phoenix, and we saw the pepper spray and everything else, and we are back for the second rally."

There were also protesters at the site.

The Associated Press (AP) contributed to this report