NEWARK, N.J. (AP) - Donald Trump, provocateur of the Republican presidential race, now plans to go the Mexican border, a flashpoint in the primary contest ever since he declared that immigrants from Mexico are rapists and drug dealers.

He will travel to Laredo, Texas, on Thursday, where he will hold a news conference at the border, meet members of the union that represents Border Patrol agents and speak to law enforcement officers, his campaign said.

The plan signaled no backing down - indeed, a possible further escalation - in Trump's feud with presidential rivals and other figures in the party. That feud was sparked by his comments about immigrants last month and accelerated when he mocked Arizona Sen. John McCain's experience as a tortured prisoner in the Vietnam War.

The billionaire's taste for payback against those who criticize him was demonstrated Tuesday when he gave out Sen. Lindsey Graham's cellphone number to a crowd and TV audience, resulting in jammed voicemail for the senator.

This was after Graham, one of the GOP candidates, called Trump "the world's biggest jackass."

Graham made light of the episode Wednesday, appearing in a video entitled "How to destroy your cellphone with Lindsey Graham." In the video, released by the conservative media outlet, IJReview, Graham attacks a flip phone with a knife, golf club, sword and more, puts it in a blender, sets it on fire and drops it from a roof.

"If all else fails, you can always give your number to The Donald," Graham says.

Others weren't laughing.

Florida Sen. Marco Rubio, another contender, told Fox News on Wednesday that the country needs a president who "restores dignity and class to the White House" and that Trump is not worthy of the office.

Other rivals commented on the furor, too.

Campaigning in Nashville, Tennessee, Wisconsin Gov. Scott Walker said he's not concerned by Trump's prominence in the race. "I used to run track and I ran the half mile," he said. "I realized there were some folks sprinting out ahead. I made sure I was ahead at the end of the race when it really mattered."

Jeb Bush, in South Carolina, was asked about the coming primary debates, for which Trump is expected to qualify based on his performance in polls. "This will be a first for me," Bush said, "so I'm not certain how all this plays out."

A day earlier he said Trump's rhetoric is "divisive, it's ugly, it's mean-spirited," but people who support him have "legitimate concerns about the country."

Meanwhile, federal regulators made public information about Trump's wealth and financial holdings Wednesday, showing he holds leadership positions in more than 500 business entities, has assets of at least $1.4 billion and debt of at least $240 million. The forms don't pinpoint his fortune, which he's said is more than $10 billion, because they report figures only in broad ranges.

But the disclosure, required of all candidates, underscores his unparalleled potential financial staying power in a longshot campaign that is roiling the GOP field.

In a speech Tuesday to hundreds of supporters in Bluffton, South Carolina, Trump kept on McCain, accusing him of being soft on illegal immigration.

"He's totally about open borders and all this stuff," Trump said.

McCain roused Trump's temper last week when the senator said the businessman's inflammatory remarks about Mexican immigrants had brought out the "crazies."

Graham, a McCain friend and one of the 16 notable Republicans running for the presidential nomination, betrayed the growing exasperation and anger of many in the party when he appeared Tuesday on "CBS This Morning."

"Don't be a jackass," Graham said. "Run for president. But don't be the world's biggest jackass."

He said Trump had "crossed the line with the American people" and predicted this would be "the beginning of the end with Donald Trump."

Trump responded during his speech by calling Graham an "idiot" and a "total lightweight," then held up a piece of paper and read out the senator's cellphone number to the capacity crowd of 540 people and the TV audience. He said Graham had given him the number several years ago.

"Give it a shot," Trump encouraged. "He won't fix anything, but at least he'll talk to you."

Trump also ordered the American flags on his U.S. properties to be lowered, an act he said was to honor the five service members killed in last week's shooting in Chattanooga, Tennessee.

The symbolism served, too, to highlight his claim that he has been a stronger supporter of veterans than McCain, despite the senator's central work in passing laws that overhauled the Department of Veterans Affairs and strengthened programs against suicide by service members.


Associated Press writers Bill Barrow in Spartanburg, South Carolina; Lucas L. Johnson II in Nashville, Tennessee, and Jonathan Lemire in New York contributed to this report.

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