TEXAS (REUTERS) - Businessman and Republican presidential candidate Donald Trump arrived in the US-Mexico border town of Laredo, Texas for his "boots on the ground" visit on Thursday, where he said he would win the 2016 election.

"The best way to win is for me to get the nomination and run probably against Hillary (Clinton). Hillary is the worst, look, easily, she is the worst secretary of state in the history of our country. She is going to be beaten, and I'm the one to beat her," Trump told reporters.

Trump caused an uproar with accusations last month that Mexico sends rapists and other criminals to emigrate to the United States. He has also promised to build a wall on the border and make Mexico pay for it.

Local members of the Border Patrol union had been ready to accompany Trump, who has outraged Mexicans with incendiary comments about immigrants, but announced early on Thursday that they had abandoned the plan after discussions with union leaders.

He said he would go ahead with the visit on Thursday "despite the great danger." A spokesman for the union's national office was not immediately available for comment.

The TV host is at or near the top of many opinion polls of the 16 Republican candidates for the November 2016 presidential election, worrying the party establishment, which fears he could turn off moderate voters.

Trump threatened in an interview published on Thursday to run as a political independent if he does not get "fair" treatment from the Republican Party.