Trump's Mexico Trip Credited to Son-in-Law Jared Kushner

Kushner helped arrange the surprise trip.

“Jared executed this thing beautifully from start to finish,” one senior level adviser with direct knowledge told ABC News.

Kushner has been a regular presence on the trail and has recently been an emerging force in the campaign.

"Jared has impressed everyone on the campaign, including seasoned campaign veterans, with his instincts and intellect,” a campaign adviser said of Kushner in May.

"He’s emerged as a quiet power whose input is sought on a wide variety of important issues."

Sources within the campaign confirmed that Kushner, who practices Orthodox Judaism, helped write Trump’s first formal address of the campaign to the pro-Israel American Israel Public Affairs Committee.

Kushner wrote a 1,326-word op-ed in The New York Observer, the newspaper he owns, in which he described Trump as being "an incredibly loving and tolerant person who has embraced my family and our Judaism since I began dating my wife."