In fact, Trump has been tweeting about building a wall for nearly a decade. Back in May 2009, he first declared that he'd "rather build walls than cling to them." Then in March 2013, he briefly reversed course on his wall obsession, citing a quote widely attributed to Sir Isaac Newton: "We build too many walls and not enough bridges."
Yet during the last 18 months, his stumping for the project has been a reliable traffic generator among his Twitter followers. In June, some 172,000 of his followers liked his tweeted rallying cry: "If you don't have Borders you don't have a Country!"
That placed it among the Top 20 of the more than 3,000 tweets sent by the president last year alone.
It remains to be seen how much longer the president will continue to mine the border wall issue for political gold among his followers. Trump said Friday he has considered using emergency powers to build a wall along the U.S.-Mexico border, a move that would almost certainly draw legal challenges.
"Yes, I have," Trump told a reporter who asked if he had weighed using those powers. "I could do it if I wanted."
Asked whether he needed congressional approval, Trump said, "No, we could call it national emergency."
--Reuters contributed to this story.
Tech from self-driving cars could solve border security without Trump's $5 billion wall