By Rafael Bernal - 06/01/16 11:34 AM EDT

The largest Border Patrol agents' union on Wednesday endorsed Sen. John McCain (R-Ariz), an important backing in what the 79-year-old senator said could be "the race of my life" against his Democratic challenger, Rep. Ann Kirkpatrick.

National Border Patrol Council (NBPC) President Brandon Judd said McCain has been instrumental in improving the working conditions of Border Patrol agents.

"Senator McCain understands the challenges we face out in the field," Judd said in a statement.

"Senator John McCain has led the fight in the U.S. Senate to provide the Border Patrol with resources to combat illicit activity and keep our communities safe,” NBPC Local 2455 President Art Del Cueto added.

While the NBPC endorsement may not help McCain win over his state's growing Hispanic population, it could help rally the traditional conservative base despite the ongoing feud with presumptive GOP presidential nominee Donald Trump.

McCain, the 2008 Republican presidential nominee, has voiced opposition to Trump, who was endorsed by the NBPC in March. In July, Trump said McCain — who was held as a prisoner of war in Vietnam — had done "very little" for veterans and questioned the senator's standing as a war hero, saying, "I like people who weren't captured."

Last week, McCain also defended New Mexico Gov. Susana Martinez (R) against Trump, saying "he doesn't get" the billionaire's attacks against Martinez. Trump had earlier said Martinez was "not doing the job" in an apparent reprisal for Martinez's statements saying she was offended by the billionaire's statements on Hispanics.

Democrats view Arizona and McCain's Senate seat — both longtime Republican strongholds — as vulnerable because of the state's growing Hispanic population and Trump's harsh rhetoric on immigration, which has alienated many Hispanic voters.

But McCain's stance on immigration has traditionally been softer than the right wing of the Republican party — he spearheaded the 2013 bipartisan Gang of Eight that passed comprehensive immigration reform in the Senate before it was killed in the House.

"Arizonans have no idea where McCain stands on immigration because he desperately tries to play both sides to save his political career. That's not 'straight talk,' that's just more proof that McCain has changed after 33 years in Washington," said D.B. Mitchell, a spokesman for the Kirkpatrick campaign.

http://thehill.com/latino/281854-bor...es-john-mccain