Sounds like the kind of thing Jesse Jackson used to love to do. He was constantly rhyming his ideas.
But the White House has put forth a relatively sophisticated PR campaign for the wall, with constant Trump appearances, public commentary, and social media posts – not to mention an Oval Office address – promoting his position. A slogan is probably a pretty good idea, even though the crowd that imagines itself as so much more sophisticated than Trump will snicker.
BUILD A WALL & CRIME WILL FALL! This is the new theme, for two years until the Wall is finished (under construction now), of the Republican Party. Use it and pray!— Donald J. Trump (@realDonaldTrump) January 23, 2019
BUILD A WALL & CRIME WILL FALL!— Donald J. Trump (@realDonaldTrump) January 23, 2019