1. President Obama, Canadian Prime Minister Justin Trudeau, and Mexican President Enrique Pena Nieto pledged on Wednesday to bolster their countries' economic ties and resist a surge in protectionist sentiment that helped drive the U.K.'s Brexit vote. Donald Trump, the presumptive Republican presidential nominee, has vowed to renegotiate the North American Free Trade Agreement to better benefit the U.S., and scrap it if he can't.