President Donald Trump once assured enthusiastic crowds that Mexico would pay for his proposed border wall — even outlining a "one-time payment" proposal as a candidate. Now he says the wall would be funded "indirectly" through new revenue streams or savings created by a renegotiated trade deal.
But despite his new promise, it's far from clear how the U.S.-Mexico-Canada Agreement, or USMCA, would pay for a barrier along America's nearly 2,000-mile-long southern border.
Big political obstacles and economic uncertainties stand in the way of the outcome Trump is predicting. The USMCA's fate is uncertain in Congress, and there are economic unknowns about how possible revenue streams indirectly created by the deal would be siphoned toward the wall.