Although the people of the US voted for BREXIT, their PM apparently is dragging her feet. You can read about it here:
And although Donald Trump is leading in the polls, everyone from the US MSM to the UN is trying to come up with ways to stop him from being elected. You can read about some of that here:
What is wrong with giving We The People that which we want?
Short answer - it's not what the rich want, so we cannot have it.