From the outset of the presidential campaign of his father-in-law Donald Trump, Kushner was the architect of Trump's digital, online and social media campaigns, enlisting talent from Silicon Valley to run a 100 person social-media team dubbed "Project Alamo". Kushner has also helped as a speechwriter and was tasked with working to establish a plan for Trump's White House transition team should he be elected. He was for a time seen as Trump's de facto campaign manager, succeeding Corey Lewandowski, who was fired in part on Kushner's recommendation in June 2016, He has been intimately involved with campaign strategy, coordinating Trump's visit in late August to Mexico and he was believed to be responsible for the choice of Mike Pence as Trump's running mate. Kushner's "sprawling digital fundraising database and social media campaign" has been described as "the locus of his father-in-law’s presidential bid".
On July 5, 2016 Kushner wrote an open letter in the New York Observer addressing the controversy around a tweet from the Trump campaign containing allegedly antisemitic imagery. He was responding to his own paper's editorial by Dana Schwartz criticizing Kushner's involvement with the Trump campaign.[38] In the letter, Kushner noted, "In my opinion, accusations like “racist” and “anti-Semite” are being thrown around with a carelessness that risks rendering these words meaningless."During the presidential transition, he was said to be Donald Trump's closest advisor along with Trump's three oldest children.[40] Trump was reported to have requested the top-level security clearance for him to attend the Presidential daily intelligence briefings as his staff-level companion, along with General Mike Flynn who already has the clearance.