President Biden is traveling to Arizona Wednesday to attend an event at the Phoenix area honoring the late senator, John McCain, yet will pass on a visit to the border even as pressure builds from his opponents to take action on the thousands of migrants crossing over from Mexico.

On Wednesday, Mr. Biden’s visit will be competing for attention with the second Republican presidential primary debate as well as a much-hyped event held at Detroit by President Trump’s campaign. Mr. Biden’s visit, according to the White House, will be focused on “the work we must do together to strengthen our democracy.”

This will be the second time this month that Mr. Biden has made a point of traveling to honor McCain. During his trip to Vietnam earlier in September, Mr. Biden visited a memorial to McCain near where his bomber was shot down in 1967 by the North Vietnamese.

“I miss him,” Mr. Biden said during the visit in Vietnam. “He was a good friend.”

Mr. Biden’s visit to Arizona will also be a campaign stop, with a spokesman for the campaign, Kevin Muñoz, telling the Associated Press that Mr. Biden plans to “continue his career-long fight to stand up and defend democracy, our personal freedoms, our civil rights and the very values that make us Americans.”

“President Biden believes threats to our nation’s democracy remain central to the 2024 election, including from Donald Trump and MAGA Republicans’ ongoing efforts to deny free and fair elections and undermine our democratic institutions,” Mr. Muñoz said.

The stop in Arizona is not expected to include a visit to the border, even as Republicans are ramping up criticism of the administration on the issue in light of the recent surge in encounters with migrants crossing over from Mexico.

In New York, a state that is expected to be a key congressional battleground in 2024, the National Republican Congressional Committee has begun airing an ad titled, “Close the Border,” which features a statement from the Democratic mayor, Eric Adams, saying that the migrant crisis “will destroy New York City.”

“Ignoring the border crisis won’t solve New York’s migrant crisis, despite Hakeem Jeffries’ desperate wishes,” NRCC spokesman Will Reinert said in a statement.

Mr. Trump, on Truth Social, has also been pressuring the most conservative House Republicans to shut down the government “UNLESS YOU GET EVERYTHING” in the ongoing government funding debacle unfolding in the House GOP conference, including a demand to “Close the Border.”

Mr. Biden’s administration announced last week that it would be deploying 800 military personnel at the border to assist National Guard and Homeland Security Department staff as well as expediting deportations for families without a lawful basis to remain in America.

However, with the recent surge in arrivals at the border, staff are still overwhelmed. The region of the border near El Paso, Texas, alone saw an average of more than 1,200 arrivals a day last week, according to a report by ABC News.

In August, crossings at the southern border rose to about 233,000 from 183,000 in July. In June, border crossings had reached their lowest point since 2021 at 145,000. 

Also Wednesday, billionaire Elon Musk will be visiting Eagle Pass, the town that has become the center of the recent surge, apparently at the behest of a Republican congressman from Texas, Tony Gonzales.

“They are being overwhelmed by unprecedented numbers,” Mr. Musk said in a tweet. “Am going to visit Eagle Pass later this week to see what’s going on for myself.” 

While it’s not clear why Mr. Musk is visiting the border, he has found himself in a legal battle with Mr. Biden’s Department of Justice for allegedly violating immigrant and employees’ civil rights and the Immigration and Nationality Act by refusing to hire non-citizens or those without green cards to work at the company, something which is illegal under most circumstances.

The Justice Department alleges that SpaceX “discouraged asylees and refugees” from applying for open positions, “failed to fairly consider applications submitted by asylees and refugees,” and “refused to hire qualified asylee and refugee applicants and repeatedly rejected asylee and refugee applicants because of their citizenship status.”