Donald Trump travelled to Arizona for a tour of the border and a campaign-style rally, looking for a boost in a red state where Republican elected officials have turned against him, the mayor of Phoenix has urged him to stay away, and he is facing a sizeable number of protesters.

Mr Trump's first stop was a Marine Corps base in Yuma that is a hub of operations for the US Border Patrol, reflecting Mr Trump’s central vow of shoring up border security, though he has yet to secure funding for a promised border wall.

Administration officials briefing on the trip said the area had seen a 46 per cent drop in apprehensions of people attempting to illegally enter the US between 1 January and 31 July, compared with the same period in 2016. In fact, migrant traffic around Yuma has dramatically slowed over the past dozen years. Once a hotbed for illegal immigration, the Border Patrol sector covering Yuma now ranks among the lowest in the Southwest for apprehensions and drug seizures.

During the visit, Mr Trump reviewed equipment used by the US Customs and Border Patrol including a Predator drone, a helicopter and a boat. He later greeted troops at a Marine Corps base amid sweltering 41C heat, signing caps and posing for selfies yards away from Marine One

But Mr Trump has faced heat from elected officials of both parties in Arizona, where he is due to thank voters who decisively handed him the state, but where activists have also greeted the president with multiple protests. The pushback has intensified since Mr Trump provoked a national furore by equating white supremacists with leftist protesters following the violence at a rally to save a Confederate statue in Charlottesville last weekend that left one woman dead when a car was driven into a crowd of counter-protesters.

The rally is supposed to be an attempt to help recapture the fervor that sent Mr Trump to the White House, with the President also seeing it as the most effective way of spreading his message. However, the mayor of Phoenix has urged the President to postpone his rally, writing in an op-ed that “America is hurting” because Mr Trump “has doused racial tensions with gasoline”.

“With his planned visit to Phoenix, I fear the President may be looking to light a match,” Mayor Greg Stanton, a Democrat, wrote. “That’s why I asked the President to delay his visit. It’s time to let cooler heads prevail and begin the healing process.”

One person who was staying away is Governor Doug Ducey, a Trump supporter. Mr Ducey was expected to greet Mr Trump upon his arrival in Phoenix, but will not attend the rally to focus on safety needs, his spokesman said.

Mr Stanton also upbraided the President for floating the idea of pardoning former Maricopa County Arizona sheriff Joe Arpaio, a deeply divisive immigration hardliner who was convicted of criminal contempt for ignoring a court order to stop detaining suspects based on their potential immigration status. In saying he might pardon Mr Arpaio, the President praised the sheriff – who voters ousted in November – as a “great American patriot” who “has done a lot in the fight against illegal immigration.”

However, White House press secretary Sarah Huckabee Sanders said a pardon was off the table for the time being.

“There will be no discussion of that today at any point, and no action will be taken on that front at any point today,” Ms Sanders said.

As for the rally, and the protests, Phoenix Police Chief Jeri Williams said in a statement that her force will have “maximum staffing during the visit”. While Mr Stanton said the city is committed to keeping everyone inside and outside the arena safe.

“The Phoenix police is always professional and the FBI and Department of Homeland Security have been great about coordinating with local law enforcement,” former Arizona GOP Chairman Robert Graham told The Hill.

While Mr Stanton’s rebuke of Mr Trump might be expected from a Democrat, Arizona’s Republican senators have been among the President’s most prominent critics in the GOP. Sen John McCain has consistently questioned the President’s judgment and cast the decisive vote to derail an attempt to repeal the federal healthcare law, and Sen Jeff Flake has become an outright adversary after writing a book critiquing the President. That opposition has spurred a furious response from Mr Trump, who has backed an electoral challenge to Mr Flake.

The President tweeted last week: “Great to see that Dr. Kelli Ward is running against Flake Jeff Flake, who is WEAK on borders, crime and a non-factor in Senate. He's toxic!”

Ms Ward planned to attend Mr Trump's rally, sparking talk that the President could take the politically extraordinary step of endorsing her from the stage over an incumbent Republican senator.

In a modest but telling swipe at Ms Ward and, by extension, at Mr Trump, the Senate Leadership Fund, a political committee closely aligned with Senate Majority Leader Mitch McConnell of Kentucky, is spending $10,000 on digital ads that say of her, “Not conservative, just crazy ideas.”

However, Vice President Mike Pence, when asked about the rally by Fox News Channel on Tuesday, said Mr Trump was “completely focused” on his agenda for the country.